I think it depends on what precisely you mean by "feminist," but by most understandings of this term, I think there are a number of male feminist philosophers, and certainly an even greater number of male philosophers who are generally very sympathetic to and agree with feminist philosophy, even if they do not count feminist philosophy as one of their research specialties.

From an armchair sociological perspective, I'm inclined to think that actually most male philosophers agree with much of feminism--including some who are nonetheless still capable of very un-feminist behaviors at times. Alas, it is one thing to recognize the value of a certain philosophical point of view, and quite another to live up to the demands of that point of view!

As a white male myself, I guess I'm answering your question in the affirmative by even presuming to post an answer to it at all. Surely the question you asked is so broad that no one could reasonably answer it in the negative. Racism exists: some people or practices are racist. Sexism exists: some people or practices are sexist. There: I've said it, and I defy any reasonable person to deny my assertions or call them "illegitimate." Now, it's a harder and more interesting question exactly how much a white male can say about racism or sexism without losing credibility on those issues, but I'm inclined to think that a white male could, in principle, become the world's foremost authority on racism and sexism, and the burden of proof would rest with anyone who said he couldn't speak legitimately on this or that particular aspect of those issues: we'd be owed an explanation why not.

Let me begin by saying that any meaningful discourse requires reason, including feminist attempts to mount a critique of reason!

Feminists differ significantly, so there is no one answer to your query, but there seems to be a shared conviction that rationality alone is insufficient to shed light on many of the deeper problems humans seek to solve. One way to ask the question could be: "Given its rightful role in any inquiry, does rationality exhaust all aspects of a given question?" or: “How does one's experience, cultural identity, gender, along with many other social markers shape the nature of the questions one raises and the answers one is willing to consider ‘rational?’"

Historically speaking, the raising and answering of significant human questions has been done in the context of educated, white, European male academics or clerics. Perhaps Descartes could sit by the fire and believe he is but une chose qui pense (a thing that thinks), but is this the experiential norm for most men and women? Where are the meditations devoted to their collective wisdom?

Remember, feminist do not debate arithmetic and so I would suggest that feminists do not critique rationality per se. Rather, feminists argue that reasoning that purports to be universal but is not inclusive of a wider range of human experience/reasoning is never "pure reason" but contextual. But this isn’t just a feminist matter! Why would anyone wish to privilege a narrow sample of one type of reasoning (significant in its own right) to the exclusion of all others?

Plato calls in his Republic for women to participate as equals in the activities of citizenship, saying that surely many women are more excellent than some men and that less excellent women should be disqualified from various roles (along with less excellent males) on account of their lesser excellence rather than on account of their gender.

I think that you are right--in age of gender equality, opening doors for women, paying for them on dates, and definitely dying for them, seem to make little sense. Why, then, do these behaviors persist? In part, they persist because many people do not fully believe in gender equality. In addition, I think that some people just find it difficult to change their behavior for a variety of reasons, even when they believe in gender equality. My husband, for example, feels more well-mannered when he opens the door for a woman, and he likes that feeling (he was an Eagle Scout). (He prefers to be thought of as a little bit traditional than as a little bit inconsiderate.) As long as we treat women and men differently, gender equality will be a struggle. I ask my husband not to open doors for me--in practice taking turns opening doors seems to work best. We can all be more considerate of each other.

The questions that you are asking are terrific! They can also be taken further. E.g. is it necessary for you to assume that there are strictly two biological sexes? (I don't think so). Or e.g. What is wrong (if anything) with sexualization of a group? What is wrong with sexualization of a subordinate group? It is not difficult to turn up inconsistencies in what society considers to be socially normative.

Here's a plausible principle: in general, we shouldn't do things that are likely to make people uncomfortable. This is particularly true if our only reason for doing whatever we're doing is that we get some sort of enjoyment out of it. And if we're in doubt about whether we're likely to make the person uncomfortable, better to err on the side of caution.

The principle is actually a broad one, as we can see if we change the example a bit. Suppose the person sitting across the room from me has a very sweet face. There's nothing wrong with noticing, but staring is another matter; that's likely to make the person uncomfortable. This is true even if the s/he has made some effort to highlight facial features. Noticing, even appreciating is one thing; staring, let alone ogling, is another.

That's the general advice. In real life, there are lots of subtleties. It's not unusual for one person to notice that another is "checking them out," as it's sometimes put, and to be flattered. That might be particularly true if the setting is a bar where people go to meet one another. But even there, the general rule is still a good one.

Maybe the simple version is this: I shouldn't be creepy. And if someone might well think what I'm doing is creepy -- even if I don't mean it to be -- I shouldn't do that either.

I just answered a question very like this one. It isn't sexual harassment to express interest in a woman in a social circumstance, at least in the first instance. There are lots of ways of doing this that are rude, crude, and stupid, of course. But it is only "harassment" if it continues after a clear expression of non-interest has been conveyed by her. If I go up to a woman in a bar and express sexual interest, it is not harassment, even if I am clumsy about it. That would make me a loser, maybe, but nothing in feminism (or in the legal concept of harassment) makes it harassment in the first instance. If I continue after she has told me to take a long walk off a short pier, well, then, it starts at that point to become harassment, and yes, women (and men) have a right not to be pestered and...well, harassed!

As I understand it, the issue at stake here is that people (and not just women) want to be able to regard their workplace as just that--a workplace. The minute someone in that place begins to give sexual attention to someone else in that workplace, the environment is changed--and changed in a way that makes the workplace no longer an entirely comfortable place to work.

There are obviously degrees of sexual harassment, and I frankly don't think that giving unwanted sexual attention (that is in no way coersive) on a date could count--either ethically or legally--as harassment. But it is different in a workplace. If you find someone's sexual interest or expressions thereof unwanted on a date, you can always refuse to go out on another date with that person. But if you have to deal with this at a workplace, your only option is to try to find another job--which these days can be a major problem, and which a good worked should not have to feel that he or she has to do, to avoid someone acting in a way that is inappropriate for a workplace. So this is not simply a "freedom of speech" issue. It has to do with making the environment of a workplace no longer comfortable for some other worker working in that place. Please respect this!

Certainly nowadays the law would require the woman to pay alimony in this situation, and I am sure there have been many such cases.

I find it hard to see how anyone who wasn't just flatly sexist might think it should be otherwise. Perhaps vestiges of sexist thinking with which we have all been saddled by our society would make our gut reaction a little different, but fortunately we have brains and do not have to be ruled by our guts.