There doesn't appear to be any pin or anything locking my mini ycomp on my bushy m4gery. Am I missing something or did I get lucky? Should I try turning it off?

Probabbly blind pinned.
We had one at the shop last week that I could not see at all.

My post-ban RRA is the same way. I can see some minor discoloration where it looks like it was welded, but there is no visible weld or pins. No idea how it is secured, haven't tried to unscrew it though.

Has there been any cases where they havent welded and pinned them? If I tried turning it, how much pressure is it to spin it off before I realize its pinned :)

its pinned in two places BDC and TDC you will never spin it off!

I would not try it. I have a preban upper that was on my preban carbine, where some bonehead tried to twist off the permanently attached 5.5 flash hideroff the 11.5 inch barrel - you can the the marks in the slots - and the receiver slot for the barrel key was damaged - now the barrel is loose even when the barrel nut is tight. I had to replace the entire upper and it is pretty much a spare parts upper now. If you have a postban, it is illegal to have an unpinned muzzle device, where threads exist. A good gunsmith can make the blind pin invisible.

it's pinned and welded on, no matter what you can or can't see, and it's a postban, so it's not threaded, therefore 'turning' it would do nothing but ruin your finish