Sorry to hear about your computer problems.* Been there, pulled my hair out over it!* Now my son has some back up thing that backs up my computer daily.* At least I won't lose my thousands of bookmarks!*
The more you prune your crapes the more they sucker.* I have a serviceberry that drives me crazy with it.* I read somewhere to wait to prune them off until after the spring flush of growth.* I haven't done mine yet this year so maybe we could compare notes.*
A sealer isn't a good idea as it gives a place for insect pests and diseases to hide.* There is something called sucker stopper that might work.* I've never used it.* See #2 and #3 here.
Here's the label.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.