First thing I would check would be angle/postition. Having said that, You need to have your setting such that you get a slightly convex weld profile. One way of telling if your parameters are close is how well the flux peels off.
Electrode Stickout may have an influence as well. I find the...
If you have a flat floor surface, machinery skates should work well. If the bottom of the object you want to move is flat, plain rollers will work, but are a pain, and would probably damage linoleum.
Would a Manually operated pallet jack work? With the right wheels, and no slope(I hope!) 2500kg...