Would you have to play 3 generations in each town Even though you complet all ltw's etc. earlier Or is the challenge complet When all ltw's etc. Are completed?
The challenge is complete when all the ltw's ect are complete: all ltws, all ltrs, all skills supermaxed and all careers maxed (note that only heirs can max a skill and a career, the basegame came with 10 skills and 11 careers if I remember it correctly, so with only the basegame you would have to move at least 3 times).
The if you complete one of the requirements (for example buy out all the ltrs before you have maxed all skills) you no longer need to think about buying ltrs, but you still need to do the other categories.
The reason for the 3 gen/town and then move, is to see how your sims change and what features stay a long time with your sims. One of my favorite things about the 4x4 dynasty was creating interesting looking sims with a townie breeding program, and that is why this requirement is part of this project.
I hope I answered your question. If not, feel free to ask again.