To answer your questions:
1) If the game was done, we'd be shipping. Judging the game when most of the play balancing and usability features are left to be put in is not a good idea.
Incidentally, it's stuff like this that makes most games have closed betas. If you're wondering why Civ IV had a closed beta, this is precisely why -- because games, by their nature, are not very fun. GalCiv I was definitely not fun at this stage in its development.
2) I'll try to put aside the assertion that GalCiv II is "GalCiv I" with a new coat of paint given that the entire planetary, colony, and military system is totally new and different.
3) On the Foreign Policy screen in the Treaties tab in the Treaty summary you will eventually be able to see the relations a player has with the other players (right now it's blank <see #1>).
4) The number keys have not been assigned yet. Eventually you'll be able to hit Ctrl-# to group something and then hit that number to bring it up whether it be a planet or a ship or a fleet.
5) We'll see what we can do about filtering techs further. Though bear in mind, GalCiv I didn't have a visible tech tree option at all, just the list.