I've done practically all base game and WA lifetime wants now, it was one of the things that prompted me to get more expansions as I had run out of things to try.
Generally I play on a custom longer life span so time isn't an issue but some were defintely harder than others, the do x amount of tombs one was relatively easy up to a point, so was the visa one, but then my adventure board got buggy and I had an awful job finishing that as I couldn't get into some tombs without the quest key, thankfully it sorted itself out after many days trying.
But doing both concurrently worked a treat, my sim did the visa LTW and her husband the tomb one (sorry I forget the exact names) and just him tagging along counted for his score. At home they were both in the police, super spys, so the athletic gained tombraiding helped their careers too.
Rabbit hole LTW's I generally find fairly easy, Surgeon has given me the most trouble in the past promotion wise, especially as my sim is neat and will keep putting her medical book away, being a bookworn never made her just read it unfortunately. Trying to find the time to learn the logic, read the medical book and keep her needs fulfilled when you get called back into work at all hours isn't easy.
I had a quick try at the architect one but I stupidly chose Bridgeport to try it in, not the best place for that as half the time you can't even get in the house or talk to the client.
I'm just about to complete Descendant of Da Vinci in my current game, she started as a teen which if you join the art club at school gives you a head start in painting and sculpting, I've been extremely lucky so far and she's only caught fire once. She rolled the sculpting career which was fine by me, I also sent them to china where I bought the incense burner and her husband has learnt mixology and makes skill gain drinks so she's had double brain power for faster learning. Also there's inventing books in the library which with her bookworm trait if i'd wanted she could have whizzed through those but I chose the workbench over books.