They won't be liking the winter, so just concentrate on giving them good light and getting them safely through to spring. If you're getting new leaves and flowers at the moment, you're obviously doing things right.

My guess is that the little white bugs are the larvae of fungus gnats - you can confirm this if you also have tiny black flies crawling around the edge of the pot. If so, then I'd be inclined to get some fresh compost, get rid of all the old compost from around the roots, and repot them into clean pots and fresh compost.

Chillis are pretty good at sorting out fertilisation for themselves. No need to go around with a little paintbrush pretending to be a bee. But you do need them somewhere where pollinating insects can get at them. Spraying with a fine spray of water sometimes helps fruit setting.

You don't want any chillis just yet - as I understand it, the temperature of the chilli is directly related to how warm it was when it was ripening. So really you'd like your fruits forming from May onwards.