Is it ok to give more character development to the antagonist. I can work with more if that is an ok thing to do!
Well I would keep it equal or readers will think it's the main character, ya know? Think of him/her as the supporting actor. Depends on your POV to I would assume.
Of course it's good to develop the antag, but you'll want to develop the protag too. If you're having difficulty with the protag, consider changing him/her to make him/her more developable. Or, if you're finding that you really are much more interested in the antag, maybe (s)he could become the protag instead (like an anti-hero). As Lmc said, it needs to be clear who the MC is.
Well... Antag can be considered to be a kind of MC too. I find the best way to seperate them is to give them completely different personalities. Or you could go the other way for a darker story-they both have the same personalities. This would make the protag question him/herself because he's like the antag in so many ways.
I'm struggling with this at the moment, too... it's just because I think villains are so much cooler! The only way I've found around it is to just squish the antagonist down, if you don't want to make them into the MC and keep focus on the protagonist, you might want to take out some parts of their character and save it for another work. And develop your protagonist so that they're just as interesting. It's great when they get into a kind of 'war' over who can have the best plot - it's a good way of getting a really interesting book going.
Give as much personality and depth as you can to all characters, in the limited amount of time they are seen.
I second Rennat's comment above. My favourite author is this Swedish crime author called Henning Mankell - his stories are nothing special, but my goodness are his characters memorable. The most realistic characters I've seen in most places. And every single one of his characters - even the most minor character who only has 2 lines in the ENTIRE novel and is never seen again - even them, you get a sense that they have a life, they have a personality, and they're real people. They're not some cardboard there just to move the plot along - they're real people, with real lives, with hobbies and a family and habits and loves and hates. And yet they never, not even for a second, take the spotlight off of the MC. Now that's skill!
I don't see why you can't develop the villain and hero at the same time. I mean, unless the reader is put into some sort of omnipresent perspective, the only time they should see the villain is when the hero's around anyway. Having said that, the villain deserves just as much development - if not more - than the hero because their descent into villainy needs to be explained (unless you're writing for DC or Marvel comics in the 40's). I mean, you typically don't find a kid in school that reaches into the job-hat and gets "Jerk".