I know this has likely already been asked, but are shifter forms totally random or are they like conjurers where only certain alignments get certain forms, or certain races?

Totally random, however note:

1) Felar can't choose all foci, so in a sense that's determined by race.

2) Some forms won't ever be selected with certain other forms. That is, you typically don't draw two forms in a foci in a row that are very very similar in their strengths.