Hey there,
1. There should be no problem in switching between renderers as long technopolies does not use lwjgl features directly, only through JPCT api.
2. It is planned that big locations would consinst of smaller locations, like districts in city. Players will be able to move between locations via exit points on map. Currently this feature is not fully functional.
A couple of quest bots has been placed to a starting location (Russian and English) to help testing combat mode. You have to do is to ask them to give you training. You will be teleported to a random location with hostile, ally and neutral units (60%/10%/30%). the fight will continue unless there are no hostiles left on the map.
3. Currently, there is no system menu, i will add one later. Btw, raft, the game uses 1024x768 resolution. On higher reso it will look as floating window without titlebar. Support for multiple resolutions is another thing to do in the nearest future.