I don't know what exactly causes the option to recruit a general disappears, and I'm also rather busy, so I don't have much time to investigate the cause.
as for changing the construction time, you can change it by scrolling to the bottom of your export_descr_buildings file and changing this section:
by replacing 20 and 25000 with the relevant numbers.Code:construction 20
cost 25000
and beware, this mod does not work with some factions who use the troops (in particular when you go into battle mode) involved; when there are model clashes, e.g. the Romani.