Hey Shaggy, my well man has a formula that I think he pumps full out for 10 minutes and if the well handles it without overpumping the casing, it`s good. For handling a household and a small cattle herd, 10 gallon a minute is good.
I got a submersible pump down 140 ft, if I`m filling a sprayer it`ll overpump the casing so I run it about 3/4ths open and clean the nozzles and come in and argue with the liberals on the forum page 
At a different place I got a jet pump about 30ft down and that will knock the cup out of you hand and I can`t imagine ever overpumping that since the water table is so high. Then I have a old stroke pump on a well, in case of the zombie apocalypse.
But you could "DIY" buy a 4" submersible pump, go down 50 or 100 ft and see if it pumps enough to suit your purposes. As far as I know, all you can do is put the pump down deeper and if that doesn`t work you need a new well.
BA, this well is only about 20-30 foot deep and I've got no idea how old it is, probably 50 years or older. I've got a 1" pump powered by a small 2 stroke engine I might try. I'll pump it full out and see how long it takes to suck air. If it can't keep up with that small of a pump It'll probably never work with a solar or wind driven pump, unless it is a calm cloudy day. 
