In answer to your questions:

1. Some mini roses bloom a lot and some don't. It depends upon the variety just as with the bigger roses.

2. Yes, mini roses are repeat bloomers.

I have found through experience with my own minis that the more decorative formed minis bloom almost continuously while the more exhibition formed minis bloom in regular cycles just like the HTs. That's not a hard and fast rule but a general trend. If you want something that blooms all the time go with the more pom-pom shaped blooms. Softee is a really good one for continuous bloom but give it room because it gets about 3 x 3 feet in size for me.