Eek! I would not throw all of that into the cat's system at one time. I don't know the answer to your questions about how to split up the shots or how long in between. I am not a big fan of over-vaccinating anyway, but given this cat is in rescue and exposed to a lot of other cats, this may be a different situation.
If vaccinations are given, I always request PureVax for my cats.
Mary Jo (Maryjo and Smokie) just went thru a horrible time with her civie Fluffy after he was given multiple vaccinations at one time (the same 3 you mention). She thought she was going to lose him, he was so sick for 3 weeks.
It may be more inconvenient I know, but it may be safer to do one vax at a time (if they are really necessary) and see how the cat reacts so as not to bombard the system with toxins.
Just my 2 cents!