'Fraid discipline is as the full-time service. This isn't second rate, just part-time. If you're going for officer, you'll get lots of preparation though and Cranwell will place a lot of store on it. Other training will do likewise I'm sure. My suspicion is that full time service personnel make an allowance for/understand the fact we're not doing it day in/day out, but that doesn't mean a licence to slack.
Formality - depends who's around. If you've a good boss who's confident in your ability then, like my lot, you're probably fine. Christian name terms where appropriate, and working as a team, all as one. But make no mistake he's the Boss, and deserves respect for that, and sensible obedience (i.e. if you're lucky you'll have a boss who'll also listen to 'Can we try it this way please, Boss...'). It does get tighter when there's other personnel around, expecially senior staff, but I suspect that's exactly the same for the full time service.