Anybody else think the starting AD penalty is too much?
It's necessary to be able to cram the undead Type into a feat.
Going by the design point values that have been reliably established from published content, a Species feat should generally be around 2-3 points of net value. The undead Type, according to the references I've seen, is estimated at 6 points -- a hefty price, since it comes with a fair number of immunities, but not quite as much as the construct Type (which costs 8 points, and has even more immunities than undead do).
Generally speaking, a penalty or drawback is worth about half the value of the corresponding benefit. Eg, +5 ft Speed costs 1 design point, but a -5 ft Speed penalty is only a -0.5 design point drawback. The "More Than Luck" Origin ability (+1 starting AD) costs 4 design points, so correspondingly a -1 starting AD penalty offsets 2 design points of benefits.
So the Undeath Apprentice feat here offsets the undead Type with Repulsive (-0.5 pts), Reviled (-1 pt), -1 starting AD (-2 pts), and -5 Blend (which, by comparison with the various Legacy feats and with Species feats that give +4 to a specific skill, we can surmise to be approximately -1 pt). Altogether, the feat as a whole comes out pretty much on par, since this comes out to a net value of 1.5 points just for the baseline effects (undead Type and the various drawbacks common to all variants), then you have another 1 point or so in net benefits for the specific variant you choose. Total value comes out to roughly 2.5 points -- which is the norm for Species feats.