Yes, yes and No. If they are growing in a pot, you can plant them anytime. Digging out an old one is gonna be hard, they really hang on to the ground and have a lot of roots (unless there's a root rot issue). Even the trimmed ones will become rang-ey and straggley in a year. When they're happy they can grow a lot. They hate indoor life, it just too dry. They love lots of light (virtually impossible indoors), a little bit of humidity (more than inside a house, less than we have on a hot and sticky summer day), and they like things to be cool. They do best where it stays kinda cool all year. If we have another harsh winter you can expect some damage.

I bought a small one from Lowes 2 years ago. It has done quite well outside, but I put leaves around it in the fall. It is also bordered one side by steps and another side by the concrete stoop...maybe that helps. :) I have no idea if it would be ok to plany now, sorry.

Rosemary can be hard to remove. My husband's mother's was 3-3.5 feet by 4-5 feet wide. They had to tie it to a car to get it out....and, only part of it came out. They had to really dig the rest out. :)