ZFR: Playing the Keepers campaign, what difference does it make what I race I choose for my Leader?? I know it affects your relations with other races, but does a leader get different skills depending on the race?
In the campaign, you'll always have friendly race relations with the races you ally, and you'll have good relations with any races that share an alignment that is the same as your
current race's alignment. You'll have decent relations with any race that is one step removed from your current race's alignment.
So, if you go Halfings -> Lizards -> Undead, then...
-As Halfings, you'll have friendly relations with Halfings (your race), good relations with Elves and Dwarves (good aligned), and you'll have decent relations with High Men (Pure Good, one step removed) and the four neutral races (Neutral, one step removed). Dark Elves, Goblins, and Orcs won't like you, and Undead will hate you more than the Evil races.
-As Lizards, you'll have friendly relations with Halflings (allies) and Lizards (current race), good relations with Humans, Frostlings, and Azracs (also neutral), decent relations with the five other races that are good/evil, and uncertain relations with High Men and Undead (two steps removed).
-As Undead, you'll have friendly relations with Halflings and Lizards (allied) and Undead (current race), good relations with Dark Elves, Orcs, and Goblins (one step removed), and poor relations with everyone else (especially High Men).
The morale of a stack is affected by the alignment of the units within it. Mixing units that don't like each other (ex. Elves and Dark Elves) will lower the morale of the stack. If there are powerful units that like you mixed in, they can keep the ones that don't like you from rebelling, but watch your race relations. Units with no alignment will work with anyone, but be aware that No Alignment is
NOT the same thing as Neutral alignment!
The race of your leader determines your starting stat values, and it also determines your leader's alignment. That said, your leader will always be cheerful (highest morale), and your leader will usually be strong enough to keep everyone else in his stack from rebelling. So the biggest difference between leader races is their starting required stats and abilities (you can't have a Lizardman leader that doesn't have swimming, but he'll initially have lower resist than some other races).
ZFR: Halfings seem to get an extremely bad deal. All they get is +1 to Res. Dwarves get the +1 Res too and in addition to that they get +1 Dam, Mountaineering and Cave Crawling.
Check whether they have more points to spend on abilities. I seem to recall that some races have more points pre-spent, and so have fewer points available for user selected spending.