For your second question, you can port over any Quake map but it won't work automatically by using the original pk3. You'd need to know a bit about mapping to do this.
I editing pk3 file and i add meta folder (for select the map in the game)
The game and map start but it's not possible to play (i think that i must to add start position for human team and alien team ?)
I convert .bsp quake3 map to .map et i open the file with netradiant.
and i think i add "team structure", but i dont understood.
Both teams require at least one spawn. Traditionally an RC, Overmind and basic defences are also provided.
Make sure you place these objects floating slightly above the ground. Placing them in or on the ground may lead to Daemon deciding to refuse their lease on existence.
These are the bare minimum. Usually you want to give teams more buildables to start with than just the spawn points. Look at other maps to get an impression of a good starting base.