A) thanks!
B) The summary should be in post #1. Sorry it doesn't have all the suggested improvements and my answers whether we will consider them or not. All we "guarantee" (as in "we already know it can and will be done") for the device is listed in #1 though.
C) ...is obviously missing in #1. We are not accepting preorders yet. We are going to set up some sort of crowdfunding or donations for the prototype development. Stay tuned, when it happens it will get updated in #1.

All your suggestions are completely sw related only. This thread is not really about the OS even. It definitely is not about applications and system functions like cryptfs. This thread is about the hardware and if/how we can build it in a way so maemo5 can run on it.
To direct you elsewhere, I'd suggest to use the search function of this forum, most topics probably are already covered for current maemo5 on N900.

cheers
jOERG