Cake; To freeze or not to freeze?
For the 1st question: can I freeze the crumb coated layers? 
Yes, you can. I've tried it before and afterwards you can smooth it out further.

As for the thawing frozen cake within 2 days, that would heavily depend on your buttercream type. 
If the climate is hot and you don't use a stable buttercream, I definitely won't recommend it. 
In my experience meringue based buttercream holds better than american type buttercream.
Hope this help.