If you go to the main page of the Mini Rose Forum, scroll down and search for "indoors" there are a few articles that discuss this. Here is one: questions about the winter (yes, it is really about keeping minis indoors). Bottom line, they really are not indoor plants, they would be better planted outdoors.

Don't give up! I have been growing mini-roses indoors successfully now for quite some time so it can be done. My advice- similar to another's - get a 2 or 4 lamp fluorescent shop light. These are very inexpensive and can be purchased at any home improvement store. Use fluorescent plant lamps in them and hang them about 2 inches above your plants. Buy a timer and set it for 16 hours. It takes 16 hours of this light to even come close to replicating actual sun. Make sure you prune off any dead leaves and dead canes. Fertilize with exactly one-half of the recommended solution of a rose fertilizer. Spray for spider mites. Your plants will be beautiful and will provide you many hours of joy. You can do it!

I do spray for spider mites on my indoor minis but Avid can be quite expensive. A good control is not misting, which doesn't do a thing, but wrapping a paper towel around the base of the plant to keep the dirt in, inverting the plant in the kitchen sink and spraying the underside of the leaves with a good cold spray from that hose spray I've never found any other use for. If you do that twice a week, spider mite will be a thing of the past.
I use Avid because I have big roses inside and turning them upside down is nothing I could manage.
It's very common for the leaves to turn yellow and drop when you first get a potted mini. They've been forced in a greenhouse and the change to dry air and lower light levels is enough to shock them. They should leaf out again and do fine thereafter.
They sure aren't the easiest house plants in the world but I've got ten of them inside, several blooming right now and they're doing fine.