Yup, pretty much that. I really hope an open source ARM to x86 translation layer will be developed in the future, right now you have to install one of them (libhoudini or libndk) separately.
ILikePigeons
It is definitely very performant. However, it was a pain to set up when I first tried to use it. First installing it, then installing an ARM to x86 compatibility layer, and then certifying the device for Google Play to work (which in hindsight isn't necessary considering that Aurora Store exists.)
Same, I do however also write all of my password in a notebook, so I don't lose them if anything bad happens.
As far as I have heard, 5th game is the last good one. Personally, I haven't really played it ever, I am mostly just playing HOMM3 and 4.
Same, World of Tanks is the first game that comes to my mind when people mention pay2win mechanics. I am quite happy that I don't play that game anymore.
GSI (Generic System Image) ROM-s do have bare-bones apps due to their nature of being mostly designed for developers. That won't really be a problem as you can just install better alternatives to those apps. The problem with these ROM-s is that they most likely won't have drivers for the camera for example. Also the phone has to be Treble-compliant and it has to come with Android 9 (ie. it has to be preinstalled, devices that have been upgraded to Android 9 aren't supported.)
Mine is 2009 15 inch model. I love it and I have been using it for more than a year. However, sometimes it is quite annoying to use, battery barely holds a charge, it sometimes completely freezes for around 10 seconds (with a lot of ata errors, I am assuming that the SATA cable is the culprit), fan are rattling and Nouveau sometimes breaks itself. The problem is that replacing all these parts would get really expensive, at least if I bought most of them from iFixit.