So although it's been a while since this has posted I will recapitulate some things to make sure I understand.
The ONLY way a sim can make money whatsoever is by using the options you described.(No opps, no job(klepto self-employment anyone?)
The heir, his/her brothers/sisters AND spouse ALL have to use ONLY those options..
Can a heir be adopted?
And could you clarify for me what you mean by number of hidden skills? I know about hidden skills, but if I get everyone to all possible hidden skills to level one it sounds just too easy.
Oh, can I go inside townies' houses? or can I just steal their cars?