b.) When I am talking GTK, I mean GNOME here, as that's what the Librem 5 will run out of the box. There's all the APIs GNOME exposes for your dev pleasure + any other that you can utilize on standard desktop Linux, including bluetooth, contacts etc. [1] [2] [3].

c.) The majority of devs that are on iOS and Android, sure. but since there's plenty of Linux desktop applications already, I suspect the initial set of apps would be these, optimally ac customized to a mobile screen.

That'll give them a functional edge from their Android/iOS equivalents pretty much from the get go. which is also the major advantage of this effort compared to Ubuntu Touch/Firefox OS - the fact that if you're on Linux. you're already on the Librem 5.

d.) This is very much ideology-driven at this point. It is very important for efforts like this to exist. It probably won't ever be as big as Android/iOS, but it's important to do for the smartphone what Stallman set out to do in the 80s for computers. And few believed in him then. I don't see how "being skeptical" is furthering any cause.

I believe in a free, open-source, privacy-focused smartphone, in the post-Snowden age and an age where war on general-purpose computing is heating up. If this ships, even in less than ideal state, I'd welcome it with open arms. I realize that others may not be so inclined, but there must be people who push the boundaries in order to preserve free computing. I count myself among them.

1 - https://developer.gnome.org/references

2 - https://developer.gnome.org/gnome-bluetooth/3.20

3 - https://developer.gnome.org/libebook-contacts/3.10