Seems Richard Sherman's elbow's all better -- 'cause the guy was healthy enough to get on the 1s and 2s at a crazy pool party in Vegas this weekend ... with his pal Brody Jenner! The two -- along with Richard's teammate Kam Chancellor -- took over the DJ booth at Tao Beach at the Venetian ... providing the beats as a bunch of young, hot barely-dressed (mostly drunk) people partied their faces off. We're told the guys were cool, took pics with tons of fans -- and gambled a little bit later that night.??