Chances are pretty high that it will work just fine with your current version of windows 10; there are a few people reporting issues, but they really seem to be the minority thus far.
What we cant say is if the next major release will work, or break compatibility for everyone.. and if it doesn't, chances are a fix won't come out for a while, if at all
Classic shell doesnt modify any core system files (It patches them in memory), so if compatibility breaks, it shouldnt damage your OS in any way (basically any issues caused should resolve themselve when classic shell is uninstalled)
so it isnt particularly 'risky' to install it.
Here is a comparison chart of various classic shell alternatives:
http://www.classicshell.net/forum/viewtopic.php?f=7&t=2399If you just want something similar to the windows 7 experience, you shouldnt have a problem finding a menu that is 'good enough'