I've been using nikon D7000 for interior RE photography. Should I upgrade to a full frame for interiors?
The answer to your question depends a lot on where you are in the level of your work and what your goals are.
I looked at your interior portfolio on your website and to me it does not appear that the D7000 is getting in the way of you doing quality work. Your interior work looks very impressive. You are clearly not a beginner.
I would say that if you are shooting only for real estate agents there is probably not much point in upgrading to a full frame camera and lens. Most agents could probably not tell the difference. However, if you are starting to shoot for interior designers, architects, the very top-end listing agents showing up with the best equipment adds to your credibility and allows to do the very best work. In the overall scheme of things your ability to come up with great compositions and your lighting techniques have a bigger effect on the quality of your work than the specific equipment you use.
Be aware that if you were to upgrade to a full frame body like a D810 or a Sony A7RII both of which are in the $3000 range you would also need to purchase a top-end wide-angle lens to get the best use of a high quality sensor. The quality glass in both cases would be in the area of $2000. So don't make the mistake of thinking that the only cost is for upgrading the camera body.