I think if you're 30 or under you're probably fine. I'd say a majority of people that join are high school and college age. Just be mindful of things and some don't mind a bit of an age difference.
There are still some oldtaku (over 30) that join or stick around. I mainly just use the site as a social outlet at this point when I'm bored.
No such thing....unless you're elderly....if anything, the older, the better chances you have to be with someone on here due to mostly likely being stable financial life, thus be able to follow through with any relationships you find on here....I don't see anything wrong with being someone younger than you if the feelings are genuine and both of you are actually comfortable with yourselves and being with each other....the only thing you have to watch out with younger people is how stable their life is, how they support themselves, and if they're actually dedicated and honest enough to pursue a genuine relationship with you rather than out of say pure infatuation rather than love.
Not at all - there are plenty of older nerds here of both genders so I don't see anything wrong with that. Might not be okay to flirt with someone who may be in their early 20's, sure plenty of girls like older guys but maybe not to that extent. Just focus on socialising and having fun, don't put too much stake into finding a partner and you'll have a great time here.
There are still some oldtaku (over 30) that join or stick around. I mainly just use the site as a social outlet at this point when I'm bored.