As you say, you need squats. They're essential. Your knees will hurt when you do them if you're still getting used to them , unless you have a knee condition outside of that. You're doing a lot of isolation stuff you probably don't need to do - direct biceps work, the calf raises, flys, shrugs, and the lateral raises (as you say) are definitely not key ingredients here. I'm sure many guys can tell you that they've added mass to, say, biceps without doing curls - I got way bigger traps/calves/biceps because I stopped doing isolation stuff and focused heavily on compound stuff.

I say that knowing, though, that you HAVE the compound stuff, you just have a lot of other stuff in there too that you don't need. One major point is that you don't need to isolate/target each specific body part, so that helps clean up a lot of routines and streamline them.

Sentinel is absolutely right, though - you've got some good stuff there and 3x8 isn't a bad setup, nor is 3x a week full body workouts. You probably need some tweaking and programming but it's not like you need a whole new routine.

One more thing about plateauing, as I had this problem once: I just wasn't moving up on bench. The problem was really nothing more complicated than that I wasn't eating enough to keep stimulating growth, and I was overestimating my caloric intake. So, along those lines, can you supply what your average daily intake is? If you're hitting a wall, 3mo. is a long time to run one program, but it could also be a diet thing.

Good luck and get to those squats man.