So for your end goal, what I would think your best bet is a combination of the new TouchOSC and CSI.
You can use Reacontrolmidi as a mapped plugin in CSI and the navigation controls and general workflow in CSI will let you fly around your projects.
If you can wait a bit, I have good news on that front. I've been spending the past couple months building a touchosc layout for csi, learning lua and putting it to good use. I'm probably at least a month out from release but I'll include the reacontrolmidi functionality and I'm hoping I can do a video about it (and csi in general) on The Reapee Blog with Jon.
To answer your questions directly:
You should be able to use realearn in conjunction with reacontrolmidi.
There arent really great tuts no. But check out Facebook group TouchOSC Template Makers. Theres a files section with layouts and different tips. Search TouchOSC on YouTube and sort by upload date. Theres a couple there but nothing great. One really long unhelpful one so be careful lol.
There are example layouts that come with the program if you didnt know that, and a really helpful github repo here:
https://github.com/F-l-i-x/TouchOSC/tree/main/examples