It is different for each person.  Some feel little to no discomfort, while others find it more painful.  My advice to you is relax.  Being tensed up can make the sensation more painful.

No.  Waxing is a temporary hair removal process.  However, over time, the hair that you are having removed will become finer and less pronounced.

Again, everybody is different.  Most people wil;l start to notice the hair regrowing in about two weeks.

You will need to wait for the hair to grow back slightly.  This is not the same for everybody.  However, the ideal is to allow for 1/4" to 1/2" in length for the wax to be able to remove it.  Every 4 weeks is ideal, no longer than 6 weeks.  This gets the hair on the same growth cycle. 

Yes, for most people, it does.  As long as you adhere to a good regimen of removal, the hair will start to get finer over time and that is, for most, a lot less uncomfortable.