While SRB2 does have 32x32 textures, the general consensus appears to be that the bigger the better (unless its ridiculously large). 32x32 textures will often either look really tiled (whether or not you are going for that) or are really tiny. I went through and while working on my textures I doubled the size of the sand flat twice.
On an other note I'm starting to finalize some of the textures I working on, maybe posting them on SRB2JAZZ to get some last opinions. However I'm still trying to come up with some new stuff for architectural stuff. I have a couple wood textures but I'm still not quite understanding what the architecture is actually supposed to look like.