I've had similar issues with pacing on tempo runs. What works for me is to break down the run into smaller segments and focus on hitting a certain pace for each one. It's not about hitting an exact pace, but more about maintaining a consistent effort. I also try to find routes with some elevation changes, it helps me gauge my pace based on how I'm feeling. And yeah, practice does make perfect, you'll get a better sense of your pace over time.
I've worn compression socks for a few years now, and I think they do make a difference. My legs feel less sore after long runs, and I recover faster. It's not a night-and-day difference, but it's noticeable. Maybe it's a bit of both - placebo and powerhouse. Worth trying out if you haven't already.