I'll send any young character as a gerneral provided they don't have that accursed 'Attuned govenator' trait.
Adoptions and marriages are a no-no. I keep the bloodline pure except in the aedui, romani and other meritocracies in which case I tend to adopt in useful bloodlines and familes if I find a S/C/V char. I am perpetually understaffed, and its more fun for me.
meh, ancillaries get in the way for me. Although I do get rid of the bored trait by making them walk around for a turn or two.
Useless FM's...don't exist for me, I need everyone I can get coz I don't adopt. Also since I don't have an army without a FM I tend to be stuck sometimes and lose territory until I can get the 'useless guy up to do some work.
Generals fight till they get old and grumpy. They they develop a fetish/obsession of some sort and sit and govern some newly conquered territory for a while.
Factionleaders do what they are best as. Pretty much the only guys I fully roleplay according to their traits. Whatever they are governs the nation and its dirrection.
Ancillaries, never move them.