My pleasure
1. Specs only tell half the story. For realtime audio it's enough that one component doesn't work properly or creates a bottleneck. Observe what your system's doing while you get the glitches - how's the per-core utilisation? What's the CPU clock rate? Run LatencyMon and see what it finds? Adjust your audio interface settings (proper driver, buffer size adequate for project stage, optimal audio rate & resolution, etc.)? Pay attention which plugins causes this most often? Try different plugin version (e.g. VST2 instead of VST3)? Experiment with plugin sandboxing modes (in Settings / Plugins)?
2. Really try getting familiar with mouse wheel. It works great for moving around the project. I only ever use the vertical bars to double click on them to zoom to centent (although this was added in 3.2 or 3.3, too )
3. Yeah, free content scaling - and other 3.2 and 3.3 features - are awesome
4. I'm 100% certain all three work, unless you're doing it on a CLIP not TRACK HEADER, then only Ctrl+R will work (I'm trying to convince support to make Alt+click work too, because it's much more convenient and works everywhere else).