this game's inheritance system functions more like life insurance; applicable to just Old Age death. non-insurance money, that goes to the household members.
though I guess you mean that the sim marries/joins 5 rich sims one at a time then wait for Old Age to happen to the spouse. high chance for the sim to loose aspiration points each time since sims of any aspiration tend to Fear the deaths of best friends; though the points from this Life Time Want would probably exceed the total of the death Fears.

Nopke is looking into it but might not make the mod herself (not her thing). She said she will share the info on how to do it though.

Hmm, I'm thinking of a couple lifetime wants that involves using the computer, which would work for popularity Sims. If blogging was actually more interactive between Sims, and if a Sim makes friends via the cyberworld somehow.

Too bad emails are useless and chatting with others don't make a large impact on relationships, but maybe the latter option would make it an interesting challenge.

For the blogging there could be a LTW to entice enough people to follow your blogs, which could also improve relationships. Although, blogging in Sims 2 currently is not the same.

about email; when I had just base game, I had a number of sims send another sim a bunch of emails then check email. when checking, Daily increased 1 point per email sent. If I remember correctly, the "friend" icon did not appear after Daily exceeded 50.
have not tested after installing current packs.

Since many of the lifetime wants are mostly about accumulating things (friends, money, top of careers), here's a thought for the laziest of pleasure sims: reach old age and never employed!