Yes, an Outpost Ship is only usable to build one base.

If you want to build another base, build at an outpost ship. After you have a good location for the base, move the outpost ship (it's usually good to escort the outpost ship with some ships) to where you want the base. Go into the fleet where the ...

Every base you build will cost you twice the amount the one before it did. This is a never ending rule that just keeps on increasing to infinity. However, if you delete one of your bases the next one will cost 25% the cost it would have. Bases ...

This entirely depends on what you are looking for the astro to do; production of fleet (production), boosting your economy, research, etc. For economy, you should be aiming for either an Asteroid or a Crystalline, though the latter is generally rare an...