They are not frost hardy which is a problem over winter but during the summer (if we ever get one) you can put them outside
Depends where you live. Mine stayed outside all year round in a very sheltered spot close to the house and lasted over 20 years. I live in East Dorset and we've had snow a few times over the years as well as plenty of frosts. It sometimes dropped a lot of leaves but they always grew back and it never flowered or fruited but to be honest it didn't get much TLC.
You can prune citrus trees to suit your space.They need more water in summer than you might think but reduce in winter.All our citrus and everything else will grow and flower better when we have a summer!