ANP, any regional aircraft is going to have weight restrictions. Some more than others. Maybe we've exaggerated the ability of the 145, but the 145XR really is a different beast. As long as your landing structural weight isn't a problem, it will go at max gross- no problem, at least according to the ATOG charts. We've had no problems with a heavy load and headwinds IAH-PSP. Turned out to be 3:32 total flight time. But I don't have a lot of experience with the thing at hot and high airports, so take my post with a grain of salt.
Although, with a creative crew- weight problems can be solved quite easily. A few empty galley carts here, some half weights there. Do a'la CHQ and leave bags, maybe even an FA.
If fuel's a problem, carve out some of the contingency fuel and cruise a little lower.