For 1 and 2 use

Code:

man test
man seqx

and look for the options you mentioned. If you don't have man pages available, there are plenty on the web and even in this forum.

For 3:
If file $temp exists and is greater than zero, compare files $missing and $temp silently ie. without much output. There will be filenames and or paths to them stored in those shell variables $missing and $temp.

Generally for obvious things like switches you might consult man pages first.