Jon Dc9
Re RA at max alt. If it says climb- you climb. Absolutely. That is sop in my company and I am an Embraer pilot.
because.......
Max cert FL in the -145 is 370 at least in our company but I know the a/c can be ferried safely at up to FL410 in order to gain range etc. It's not illegal as it's a non-revenue flight. Therefore a bit of a pull-up even at maxalt is a bit of a non event.
If the -145 pilot needed or wanted a higher FL he only needed to ask. So I see no reason for him to turn off the squawk. After all if the reason for no climb was because the higer FL was occupied by the 737, he'd hardly want to go up there, would he?