8 degrees from PW to 52 degree gap is fairly wide. A 50F would split the difference. You might want to get the T100s PW in, then gap the wedges from there. That would get you to 3 options:
1. Add a 48
2. Replace the 52 with a 50F (and adjust the 56 or swap to a 54 based on further gaps)
3. Stay with the setup and be able to adjust the PW to meet the distance gaps from the 52 with partial swings.
In any event, no sense in empirical guessing. Consider a wedge fitting to get the right wedges the first time.

Sounds about right, four degrees. I have 44, 48, 52 and 56, based on my fitting. Also have a 58 for fluffy sand and softer fairways, which I sub for the 56.

It appears to be a solid wedge setup. In my case, I use a different wedge+grind setup that depends on where I play: firmness of the ground, grass, weather condition/forecast, type of bunkers, firmness of the sand, etc.

On the other hand, you need to consider your swing. Are you a digger? Do you brush the ground with your wedges?

To be honest with you, the best option is to follow what your fitter recommended.