If you were able to install Bazzite then installing graphene shouldn’t be any harder than that. It has a web-based installer that was pretty easy to use as long as you follow the instructions.
The pixel 8 will be supported through the end of 2030 (graphene support follows the same timeline as Google because of firmware-level updates that are still needed from them) so you could still get a lot of use out of it.









It can be hit or miss, really depends on the bank. I’m in the US and mine worked fine after I enabled a compatibility setting in the app list, but that’s kind of anecdotal. I think there is a community compatibility list somewhere of banking apps that work/don’t work on GrapheneOS.