@Lunatic Wolf:
1. You can't really use patches in levelASM, as patches always change the whole ROM's code. Making a patch only work in a certain level can't really be done by pasting its code in levelASM.
2. Don't know if I get what you're saying here... No, I'm pretty sure levelASM won't erase other patches' code, unless they hijack the same address or use the same free space.
@Danos:
1. Create a secondary entrance on the pipe (by clicking on the door button with the 2 on it), and make the screen exit lead to that secondary entrance (by clicking on the first door button, entering the secondary entrance number you chose earlier instead of the destination level number and chacking the first box.)
2. Click on the second door button (the one with the 1 on it) and change the number in the "Screen number of entrance" field.
3. and 4. Explaining that would take way too long. Have you checked the Tutorials forum yet?