1) I am currently playing with Alex.exe on Hard/Medium. AI hires quite a lot of mercenaries when it's in dire need of fighting men and has an FM. For example I got attacked by 3 Ptolemaioi armies in one territory and after I defeated 2, AI "made" an additional army composed solely of mercenaries. The similar thing happened when AI was fighting for it's survival and all of their regular armies were crushed. The services of highly trained assassin become very useful then (my sole assassin killed 10+ enemy FMs. No FMs roaming around=no merc armies).

2) Never saw that in EB, no matter what engine.

3) just use the -nm at the end of shortcut target line. This will disable the movie from playing at all.