I've pretty much lost the last three days of my life doing a self-imposed crash course in Reaper v.6 and I'm pretty impressed.
I don't make as much use of hard edits as you do (I tend to crossfade everything even if the fade only lasts a tenth of a second) and the video that I have used as source is from only two cameras. That means that I've had to create several virtual cameras by using digital zooms within the source video. When shooting in low light, that does rather mean that the quality goes a bit stinky poo!
Your use of multiple cameras seems to have sorted that issue very neatly. I particularly like the positioning of DrumKam. How many tracks did you end up using in Reaper?
I've also found that I have to be quite canny in preparing my materials. For my first attempt I (eventually) loaded up FIVE 3-minute videos, being the two source videos plus three virtual cameras, each of 1.6Gb. So it crashed of course. My new editing PC has 16Gb of RAM and a GeForce 1660 Super graphics card that can handle 6Gb.
I'd love to share some of my output (gosh, I'm so proud of myself!) but there are reasons why I can't share it here until after a radio program on 6th December.