I taken care of cats, dogs and rabbits for the past few years and I only take one booking a time (so I spend everyday at your place with your pets only).
I would give your pets a lot of affection (be it hugs or playing) and know how to set boundaries. I can also help you train your pets (based on what you want) and it will be easier for pets who are foodies.
I have trained cats to walk on leash (after wearing an escape safe harness).
For cats who are used to be touched and carried, it will be easier to get them to get them to wear the harness once he/she trusts me.
Otherwise it might take weeks, before I can put the harness on after I get them used to be touched and carried.
There will be 2 of us for the pet sitting and your pet will not be left alone for more than 3 hours....