isnt that a good thing for security if somebody loads a debugger, then it will reboot? wont it make it slightly harder for the unpacker?

thanks guys for answering my first question.

next question on similar basis, can you use 2 packers on one program or would it not work?

also, if you had a packer, any packer doesnt matter which one, for example fsg or upx if you hex edited the code slightly, and the packer still worked, would that mean the person trying to unpack the program might not be able to do so using a normal unpacking program? would they have to do it manually?