ad 1: Fairphone delivers the FP5 with their fully Google-certified “Android OS” by default. You cannot remove Google apps from it (unless you are a really well-versed IT guy). /e/OS is a degoogled Android by default which can never guarantee 100% compatibility with all Android apps, but spends a lot of effort into supporting as many Android apps as possible (I use /e/OS myself, and currently there is only one app I cannot run).
ad 3: I have been able to use a 2TB SDXC card in an FP5. From what I know, 2TB is the maximum the SDXC standard allows.
ad 4: The FP5 supports one nanoSIM. The other SIM you can use with it would be an eSIM (a virtual SIM, not a physical one).
ad 5: Fairphone aims to support the OS beyond 2031 (they aim for 2033). Once Fairphone has to stop providing further updates, the phone will still work, but in a way “programmed aging” will come from the “outside world” – sooner or later app developers will no longer support older Android versions. Custom ROMs (like /e/OS or others) have in the past always been able to provide longer support for the OS than Fairphone themselves (Google certification is extremely demanding for Fairphone development, and given custom ROMs do not strive for it, they can support longer), and I would think this will probably be the case for the FP5, too.
