I recently started painting my office. I was surprised to find that what looked like a bad drywall job was actually joint compound used to cover up two layers of wallpaper that covered painted plaster coated blue-board. Instead of adding yet another layer to the mix I scraped back to the plaster. I tested the walls with a cotton swab that had rubbing alcohol on it and believe the walls were painted with oil- based paint. This is what I have done so far:

Washed
Patched and sanded
Lightly sanded the entire walls
Washed
Primed (using oil-based primer)
1 Coat of Latex paint

Now that I have a solid color on the walls, I see a couple places that need more patching. I'm afraid that if I patch now when I sand I will damage the fresh coat of latex, because latex tends to be gummy.

Would any one with a similar experience have insight into whether I should wait for the paint to cure before patching. If so how long would that be? Also, should I use oil based primer or latex primer to prime the patches?

I know, that's a lot of info. I just want to make sure I give all the information needed.