[albee1952]

Things to consider re latency:
1-playback buffer needs to be low(64 or 128 are usually okay)
2-plugin latency matters. Under Mix Window Views, check "Delay Compensation" so you can see what is really going on. If you see numbers higher than 10 samples(plus or minus a little), then plugins on that track(s) are adding latency(no big deal when mixing, but bad news while recording). You may need to try different EQ or Dynamics plugins while tracking(and Waves L2 is adding 64 samples of latency, no matter what else you do).
3-plugin latency on a MASTER track will also mess up tracking(remember that Delay Compensation works by making everything else later, to match the track with the highest latency).

Re other issues:
1-Guitar rig(and most amp sims) are notorious CPU hogs, so try freezing or committing as you go(so you only have a single GR plugin "live" at any time)
2-Snaps and pops; UN-check "Ignore errors during playback".(and see #4)
3-The Focusrite is USB? Is it connected to the front of the computer or directly to the motherboard backplane(assuming this is a desktop)? The backplane connections might work better(its worth a try).
4-the Z270 Tomahawk is sort of an unknown(chipset can make or break a PT setup).
5-maybe review and re-do all the system tweaks(and note that sometimes a Windows 10 update will reset some of them)

For future reference, "VST" is a plugin format by Steinberg. "VSTi" is a virtual instrument in the VST format. Most of us use "VI" for Virtual Instrument plugins in Pro Tools.