A problem with paladins in particular is 'the code'. Because paladins have a code, people feel entitled to an opinion on how you should play your character. The DM even feels he should decide whether you fall or not. That's a massive design flaw. It's horrible.

Any player, before rolling a paladin, should sit down with their DM and explain to them, what the code means to this particular character. Never mind what the book says - just reach some agreement on what it is this paladin has to do and not do.

Anyways ...

Roleplaying - ironically - is not necessary. I've been playing for 30+ years, and I remain as crap at it as I was when I was 16. I can do in-character dialogue, but other than that, I've no nothing =)

However, I played with a guy once. It wasn't that he couldn't roleplay. He was just shy, and let the rest of us take the lead and do most of the talking. But he was a cool guy regardless, and I regret he's no longer at our table. I also really regret that we never ... you know, found the key to unlock him. I sometimes feel that if I would just have shut up once in a while, he might have had his chance to .. I dunno.

Just remember: There really aren't any good or bad ideas. Your DM should be an enabler - as long as what you're doing is something that's even remotely realistic (in game) and within the constraints of the rules.