Is it fine to have, say, a Human cleric worship a Deity of a racial pantheon? Specifically say, the Dwarven pantheon?

I was looking for a deity that fits a concept I'm working on and found just the one. Unfortunately, I have no wish to play a dwarf, and can't find any others nearly as good.

So would it be acceptable to take the deity anyway, despite not being of the typical group of followers?

Why not? We had a major PC who worshipped a largely drowish diety, or at the least is under the drow pantheon. Id say its less likely though for an elf to worship outside the Seldarine. There are humans who worship Orcus, a monster god. As long as it makes sense for your pc, i dont see why not. With that in mind, read up in the faiths subforum before you do so just to double check.

It's acceptable, but personally I think it sounds a little suspect -- you want to worship a dwarven deity, just don't want to play a dwarf? From what I understand of the dwarven pantheon in particular, there are very few non-dwarf worshippers or priests. Are you sure there isn't a human god that works better?

I would say this is allowed, but I'd come up with an excellent and reasonable reason for how it came about. Also, be aware that the DM monitors the RP of high-level clerics particularly closely to ensure that the character deserves the mighty powers granted by the deity, and that I would have trouble believing that not only a human priest of a dwarf god would exist but also be granted its highest blessings.