This is the little forced arangement my peppers reside in now. Last winter the missus put her foot down and refused to let me overwinter all the 5 gallon pots the pepers were in inside the appartment so i improvised. The thicker trunked ones are the habaneros i was talking about. They're almost two and a half years old and still going strong.
And trust me they can take abuse... i started them in soil, left them in it for a year, overwintered them with no additional light in my semi-dark living room, switched them to hydro for nine months and them back to the arangement you see in the pics from last fall untill now. They've been neglected, underwatered, overwatered, chopped, starved for fert and over fertilised... still kicking somehow.
If you want yield, top them when they reach four--five sets of leaves so they ramify. If you want trunk thickness, let them grow out untouched.
They can take a LOT of root reduction... more than 60-80% if you're lucky and the plant is in good health.
If you want a lot of flowers try to get as much rammification as possible because flower buds form on nodes. More nodes, more flowers. Also remove the first flowers that appear so you get more vegetative growth and stronger plants.
If you like it spicy and want heat, don't water untill you see a little leaf dehydration.
What they like best to grow is a lot of heat, a lot of water, a lot of fert. If you don't have fungal issues, mist them often with very weak fert sollution.
Over winter don't let them flower. Let them concentrate on surviving with low humidity and low light indoors without the added stress of flowering and fruiting.