In the UK the biggest EMB145 operator with c. 20 machines did not have the reversers fitted - in order to increase payload.
There was no use of Flap 22 for landing except in CATII although experiments in the sim suggested it woulda have been better for those famous Embraer gusty approaches (dontcha just love the cork in the atlantic feeling).
As for runways anything down to 1600M at Jersey and Aberdeen at around 1700M but both needed thinking about in the rain performance wise and no floating on touchdown to get stopped comfortably.