Nice one, khephren. DPaint can really be NOT replaced at some tasks. I made an experimental siet completely with DPIV gfx, now where did I put it?
About degrading: Most stuff will work but there is some soft that it just won't work no matter what. Specially software that _needs_ slowram. I once had a demo which only worked if you had theso-called slowram, and I found no program for my 600 that allowed me to fake this kind of memory. Also, many MArble Madness copies I found I didn't manage to make themwork. Only the HD-fixed one did.
However, it's the least of the lot. Most programs can be get to run when you degrade, and definitely use softkickers. They are a very helpful thing. I use TUDE to softkick onto 1.3, and skick to softboot onto 3.1 (I need 3.1 to use Musicline Editor and AHX)