Oh Goodie! My favourite part!
Well, this challenge was all about getting a head-start. Certain sims can be relied upon to help out on a regular basis. Appaloosa Plains is pretty much a must. My starting sim had the traits
friendly
charismatic
cat person
schmoozer
ambitious
You basically need to make your starting sim a cat lover in order to make friends with cats as easy as possible, and no pre-made sims fit the build. Maggie Gray is a cat person, but this is much easier with charismatic and friendly.
Next, you need a motive mobile, naturally. I moved in the Martingale family, and also the Singletons. Sophia bought us a motive mobile, and Booker bought us a collection helper and a nice expensive car to complete LTWs.
Cruz chose the Arc Builder LTW, and adopted the necessary pets and collected the bugs and fireflys - after clearing caches it did actually work on my challenge file!
He also took the Animal Expert LTR
Benjamin Schmidt was charismatic and friendly, and was already BFFs with his dog, and a couple of people, so he was a good selection for 'Fairy Tale Finder' LTW, as these gave him a headstart on the requirements. Being able to spam the same interactions with pets is a absolute must.
Hailey Shepherd was a dog person, and already friends with nearly all the pets in the neighbourhood. While moving in Hailey we also took Bennie Hennessey, and immediately aged her up to choose Zoologist.
Fulfilling wishes, and supplementing with some sculpting helped out for a quick 10K LTW change.
Once we had a unicorn, we moved in Honey Darnell, who was already lvl 10 riding skill. Combined with the unicorn's lvl 10 racing and jumping it was a very quick race to complete the Jockey LTW.
Maisy Miller was moved in and aged up to chose Animal Rescuer.
There was a LOT of pets and sims coming and going from the household, and the trick to making and keeping so many pet friends was to move them out with 'spares'.
The trick to getting so many LTHPs for the pets was to place them back up for adoption once they had completed all wishes, then adopt them again. They would immediately spin lots of 'sniff so and so' wishes, or 'nuzzle so and so' and even a few 'become BFFs with so and so'.
Maisy also completed the Horseworman career, by moving in Chuck and Shadow Hobble. Shadow sells for more than 11K a pop without any additional work, and the game doesn't care that it costs you more to buy her back - it only counts when you sell, so buying and selling shadow several times completes this career easily. There was no need to hurry, as in between shadow spun lots and lots of sniff wishes.
I never kept a pet bowl for longer than it was needed to complete eat/fill wishes, or a litter tray. Hay bales are great for spinning 'scatter hay' wishes. And for keeping animal moods high, it was important to keep them brushed, loved and happy. I left lots of apples and carrots lying around for the horses so they didn't have to wait to be fed them, and always had a salt lick handy too. They can double up on a standard salt lick and a celestial salt lick aswell.
Towards the end, I only had Honey and Maisy left, and moved in a random pudding-faced sim, who usually have no skills - perfect for killing of Honey (who is also charismatic and makes friends easily) and then spinning the 'oh my ghost' opportunity. Somewhere in there I changed my starting sim's traits and bought the graveyard and moved Breezy's gravestone and stole it. Then when I got 'oh my ghost', resurrected Breezy.
And I think that's most of the main things you needed to do to complete this one quickly.