Nope. I have done this many times; I assure you it will be fine.
Yes, you can. The easiest approach would be to simply install Cinnamon Desktop, rather than try indivudually installing muffin and metacity and what not...
sudo apt install cinnamon cinnamon-core
Comes with Nemo File Manager, which I prefer, anyway.
Cinnamon is the D.E. used by Mint, but I will plainly say, it works very well on Zorin and doesn't bog down after using it a while.
In the meantime, enough users have voiced concerns on the issue, I will go ahead and get started on it. I will tag you with @WillSo when they are complete, should you still need them.