For wells with no recovery and no stabilization that you need to purge and pump and then sample, at what rate do you sample?

Sample at the lowest rate that is practical, in the range of 100 mL per minute is a good practical lower limit. If you have particularly large bottles, in the worst-case scenario they will take 10 minutes to fill. Still try to keep the rate to a minimum so that you get some yield, but at the same time try not impart too much drawdown.