I don't like to answer posts with other posts, but some of the information you may find handy. At the top upper right it says search and you can put in key words and look for other info. I copied off one of the previous posts for you with some good info. Anywhere your mouse goes over a link you can click on it and open it. As far as I know these are all still good.

As far as your question goes I would think your roses need repotting in a much larger pot. If you're keeping them indoors there is nothing stopping you that I can see. Even if you want to move them outside after the temps warm up sounds like your yellow leaves are from the roses becoming rootbound. If I understood you right you have them in a 4" pot? Ok, I just reread your post, if the roots are coming out the bottom this definitely needs transplanting. What size? I'd say at least 12" container and you'll probably be transplanting from that after a few months if your rose continues to do well. I transplanted one mini rose from a 12" pot it had been in for just a few months when the leaves started turning and found it rootbound. I put it in a 15" container next. I don't understand how many individual roses you have, but you do need a much larger container. Sounds like you're doing well with the spider mites and look for, I believe it's Oldroser's thread or post about growing minis inside. If you do have individual roses you might want to break them up into separate pots, if they're all just growing from the same plant leave them together.

I don't grow roses indoors but there is some good info on here instructing you the best way to do it and some say they are very successful at it like Oldroser in some old threads I found.

Good luck and I hope this helps you out.
Leslie

Here is a link that might be useful: previous questions