A router is at the top of my list for “nice to have, adds a lot of value, but not absolutely necessary for basic projects” tools. I still don’t have a router table after 6 years, just a Makita plunge router that I got for $100. Great tool, but not 100% necessary if you’re just trying to make basic tables and such.
Windex to clean, let it dry for a bit, then a layer of gluestick has always worked for me, as long as the bed heats to 60°C for printing. The z offset has to be a bit different for PETG than PLA, which can be a bit tricky. I think (been a whole since I’ve printed PETG) it had to be a bit higher than PLA, so it wouldn’t “squish” as much as PLA. Seemed a bit counterintuitive, but it solved most of my problems