Getting ready to start my first major service and had a couple questions...

1. If I pull the valve covers with an almost full load of oil, should I expect a large ammount of oil to come out? I ask since I just changed the oil two weeks ago but didn't have time to do my first valve adjustment job. I guess that I could drain it into a clean container if needed and then reuse it, if required.

2. I've seen lots of pictures, videos, etc showing the use of a cut down feeler gague. Is there a special way to cut down a full size? Dremel cut-off wheel, tin snips, etc? I assume that it doesn't matter if there is a rough edge since it would be a bit longer than needed and thus the non-factory edge wouldn't be involved in the procedure.

Thanks in advance