If my paladin takes the Unsanctioned Knowledge feat, can each spell be taken any of the listed classes (e.g. 1st lvl spell from cleric, but 2nd lvl spell from bard, etc.), or does he pick one of the classes listed and has to choose all the spells from that one class?
The language is a little ambiguous, but I think the least restrictive reading applies. (ie. read it as 4 separate sentences "pick one 1st level spell from...", "pick one 2nd level spell from...", etc)
