problems cutting square holes with my powermax 1000!

i have a powermax 1000 using the wincnc program and i cant seem to cut out holes without having a very noticable bevel in the metal. I have slowed the machine down to what is recommended and have the amps turned up to 60. im kinda new to alot of this. I am cutting 1/2in metal and from what ive read my machine should cut up to 1in. any help would be greatly appreciated! I also would like to know how to get my lead to go up and down between cuts. Right now it will cut a hole and just slide to the next one. Problem is when the lead moves to go to the next hole it rubs on the slag and moves the metal. Thanks