Can only help you with #1

A single compression test is just a number. While if the numbers were all below
say 90 psi, then there might be trouble. But other things must be considered.
How do the plugs look? Is there any "blue" exhaust? Does the engine run smooth
and get good milage? Use alot of oil?

The best use for compression readings is to develop a history. If every year you
take and record the compression you can see if anything is happening. If you
want to go on a long trip you can take the compression reading befor you go and
compare it to your compression history.  Then rest assured that your engine is
OK or......not.