Quite a quick one. Certain talents on the Untouchable Elite advance only list 'Willpower' as an aptitude and nothing else. Does this mean that anyone buying them can only count as having one Aptitude (if they possess the Willpower Aptitude) or should we assume it to be 'Willpower, General'?

Those talents have only the willpower aptitude. There's a note somewhere in the book (I think in the Character Creation chapter) which states that some particularly difficult advances only have one aptidute.

Cool. Must have missed it.