Thank you for sharing your brilliant strategies! I never think I will do well in these challenges. mostly because I don't practice a lot and partly because I'm not competitive enough. I always end up having to fun in my file to keep my sim on the straight and narrow, and I always play very whim oriented so my sim always gets to pick a lot of what she is doing which makes skilling take more time. Also, I had decided I would make this a solo mission, which in my mind ruled out a wedding.
However, I did learn a lot about the athletic skill and the power of moodlet solvers.
My sim spent her first 48 hours at the gym working out and working on comedy and charisma. She initiated a group conversation on the treadmill to tell jokes and make gentile conversation while always staying super energized from full moods, energy drinks, watching sports (mostly for fun) and having the trainer tutor her. The poor trainer was never allowed to join in the conversation but she did take the time to introduce herself to them after they became friends.
Then she went back home where she started her garden and did all the insipred skills while tending it. As soon as they were done, she finished of the last levels of charisma and comedy before starting on the focused skills.
The one major mistake I did was having her read a herbalist book instead of a fishing one, if not then I could have maxed fishing too I think.