Good questions! I'm not a lawyer, but I think in many US states you can use any last name you want to as long as there's no intent to defraud anyone (banks, credit card companies, employers) by doing so.
Of course, the federal and local governments would probably have some objections to a man's simply adopting (for all purposes) his wife's last name, since it's VERY uncommon and we're not QUITE yet to the Fourth Reich practice of identifying everyone primarily by Social Security Number. In the official view, tho, it would play hell with tax rolls and jury rolls if they allowed it to happen.
In the case of two-name hyphenations, which I personally find unattractive and cumbersome, you may even have to take legal steps to get both parties' last names legally changed to the joint one. I've never asked anyone who'd adopted such a name (couldn't stop laughing).
Does a hyphenated last name (his and wife's) make a man less manly? No, but most other men would consider him so, right or wrong.
My personal opinion on the whole surname matter? I think wives should be encouraged to retain their birth surnames rather than subjugate their own identity, even symbolically, to their husband's. It would be no more confusing than the surname mess we have already in the US due to divorces. I've said here before that by the mid-90s, my two kids had exactly ONE close friend between them who had the same surname as the mother, due to divorce and re-marriage.
My wife of 28 years uses my last name and always has since our marriage, altho I encouraged her to do "whatever she wanted" at the time. Too rooted in tradition, I guess. (My 20 year old daughter may do differently when the time comes.)