Well, one thing speed-related that's broken in JJ2 is the shoes. They should work like JJ1 shoes, speeding up Jazz or whoever is your character beyond his regular running speed. He can sustain Olympic pace speed until he stops wearing shoes, which is an allotted amount of time that varies with the shoes, I guess. In JJ1 that time is only about 30 seconds to 1 minute, by my horrendous estimation.

Another unrelated topic is that of armor. Comparing DanZeal's JJ2 CTF map Facing Worlds to the original Facing Worlds in Unreal Tournament 3, the original map has helmet armor, so I think that helmet armor would make that map more realistic.