In regards to the chemicals, I would wait until the pool is full enough to run the pump and filter before you add any. With regard to the well pump, I've had a 35,000 gallon pool for 5 years now, and I have filled it completely 3 times in the first 4 years of operation (I won't go into the multiple reasons here!). Anyway, it takes 3.535859 days to fill a 35,000 gallon pool with a 365 foot deep well ( I'm sure every well is a bit different). The trick here is to run at least 2 hoses so that the pump never cycles off. The hardest thing on a pump is starting/stopping. You may have to pause on filling during shower times, and laundry times (due to lack of water pressure), but otherwise just let it run. My well is now 15 years old, and is still running just fine. Good luck.