In my Demo I have manually edited the res in the setup file to match the res I set in game. No idea how the res I picked will display on different devices, but for now I am happy with it. I assume it will give a border on some machines, but I am happy with that, at least on my PC (when I maximize it or run it in full screen mode).
I am hoping AppGameKit will scale it as best it can for any device. I am quite looking forward to seeing a demo running on any phone at the min lol.
As to whether to write in tier 1 or 2. If you are a c++ coder already then use that, it's bound to be faster than tier 1. Obviously it may be faster to prototype an idea in tier 1 even so. I am in the position of really having to use tier 1 as I am unfamiliar with c++, so it's a moot point for me. Still not really having any real issues with it, so it's all good fun.