These are my ways of getting around without being kicked, though i still cant do anything besides walk & talk.

either shift-key walking, stopping at constant intervals, if you dont stop it will eventually kick you.
or not shift key walking, just that you tap a directional key, stop for a second, then tap a directional key again. <-this is how i get around.
i am not experiencing chat lag however. you also cant punch people
you can also jump if you are really careful about the jumping.
however if you are stuck underground your best bet is to try to do anything that would get you kicked, jumping while mining, running around in the block your stuck in, etc. if you do get kicked it SHOULD log you in somewhere that isnt inside a block. if it dosent, then you are out of luck it seems

Could it potentially be fixed if we switched to a 1.3 temp map? It is out today.

Im really not sure, the problem still isnt solved. It may have something to do with the update, perhaps a change in the game requires a change in multicraft that they are fixing, but i cant find anything on the web about it. I think its best just to wait, because i cant find any faults in the config, which is what makes me think its something to do with hosting.

well i guess last time i left i was underground so now im stuck in a 1 by 1 hole underground not sure if im in lava but im burning cant move and i have a black strip in the middle of my screen and i can see the underground....and on top of thati have no pick....so ya

It's not just the no-cheat that got broken... everything isn't working. Like... everything.

Later tonight I'm downloading our server files and will try to solve the problem locally, but until then I'm installing a temp map.