well I have solved that problem with a mod

no caps, just spam frigates, killing a thousand pirates is much more harder, I usually just make my fleets sit one jump outside of the pirate base

4 Ai, that one was a piece of cake, same with the military and the civilian research, by far the easiest is probably either jump to another star, travel to a worm hole, or create a map

This thread is so old that it's probably considered better to start your own rather than bump it.  It contains some reference to old bugs which have since been fixed.

Yes, the conditions of the achievement clearly state that you must defeat X hard enemies on your own.  That means no allies allowed.  This is because it's possible to load yourself up with allies and lock the teams.  Especially with the new extra-high difficulty settings, it'd be an achievement to actually lose here.  Typically these achievements are completed by locking the teams and forcing everyone to be enemies.  So long as there are five "hard" AI enemies, you get credit for the achievement once you win.

No, you don't have to do that, you just have to defeat them.