I can't post the whole schematic because this actually a patent in development and I have been sworn to secrecy.
Q3 is there to ensure that C2 is completely discharged before the next timing sequence starts. I found that C2 discharges to slowly on it's own, and then you end up with a irregular timer.
I’ll add the 100nF across to the IC.
The regulator idea makes sense, but won’t it affect the MOSFET switching? I still need a reliable circuit to switch the MOSFET.