Yeah, that’d be nice. @keesj?

I would like if possible use opensource on my phone, but I still needs some apps like ‘NS reisplanner’ provided by the Google Play store.
You may know about the other possibilities of downloading apps only available from the Play Store while not using the Play Store itself (as documented in the Alternative Apps(tores) topic mentioned by @paulakreuzer). But apart from the less trustworthy options mentioned there (Evozi, 1Mobile Market etc.) I want to emphasize the open-source program Raccoon, which I’d put more trust in. It can be installed as a client program on a desktop PC and just extracts .apk
files from the Google Play Store (you still need a Google Play account, but it could be a dummy account and it doesn’t need to be linked to your phone). In particular, it’s also available for Linux (for German speaking people see this German blog post and the Droidwiki entry for more info).

Talking about features, one thing I would like to have changed by default is the DNS, so all requests sent from the FP2 would not go through Google’s DNS servers. Another feature I would like (also for the regular release) is a prompt for split passphrases for protecting the encryption key and the lockscreen without the need for additional apps here.
Nice feature requests. Is it possible to easily configure the DNS stuff such that the Google DNS servers can be replaced by other servers?

And especially these people could compile it themselves anyway…
I don’t know yet how the update process will be organised, especially concerning self-compiled versions. And recompiling the image every time a new update is published, wouldn’t be really practical to me.