I've been able to transfer generic and named retinues around freely. (As long as I wasn't trying to give one guy two poets etc)

However I can never get more than 8 retinue characters for any general.

This makes it really hard to swap retinue between two generals who both have their full complement. I'd like a 'dismiss retinue' button or something

When I switch faction heirs, I usually get the 'disinherited' vice which is a -1 influence.