I know exactly what the OP is going through, I've had both issues. With my old workstation computer that Zorin is on, the touchpad can by stuttery/twitchy just like the OP has said. And on my MSI gaming machine. My Corsair K95 Platinum mechanical keyboard, doesn't usually power up properly with the computer on the first try, and requires a restart, or further restarts, until it does connect properly.
We can't simply write these issues off as distro specific. Cause both OS's are based on Ubuntu, so all I am saying is. If we figure out what is going on with the OP's machine, the results of that, could also benefit me, as well as other's.
So I will be watching this thread closely. Also, how are things going since you installed Synaptics?