2 quick questions!
 

1, What items will reduce the leadership of droids besides engineering badge? someone mentioned Royal Hammer and Horn of King Borg but the description is "reduce leadership requirement for dwarves"...so is droid considered a dwarf? it is indeed a dwarven unit as indicated by the unit list.pdf in the index, but it sure doesn't look like a dwarf to me...maybe something got lost in the translation here?

2, Ghosts and cursed ghosts have good physical reduction(50%!) but what do i do to prevent them from over-flowing? that is, they suck blood and gain new units and lose control because their total leadership exceeds my hero's leadership.

When you look at a units stats, it has an icon in the upper right for its race (mouse over it to get a little info about that race). Droids are made by Dwarves, and are considered part of the Dwarf race.

Ghosts are rather finicky. I would suggest either keeping them a little under full size, or being very aggressive with them. When they are out of control, cast 'heal' on them to do small bits of damage (or big bits!) to bring them back under your control. Keep a stack in reserve for extra ghosts.

thanks for the response.

so Royal Hammer and Horn of King Borg will work on droids? c/d?

Yup, they both do.