From what I understand, the high school diploma is a Saudi Health Ministry requirment, not an SRCA requirment, which is why we are finding out about it so late in the process. So I am not really frustrated with the SRCA, it is just another hoop to jump through...Just when I thought the only hoop left for me to jump through was getting through airport security!
As far as documenting employment, you will have to ask the SRCA HR department, if that is who you are getting recruited by. If you are going through Action Aviation, I suppose you would have to ask their recruitment rep. Almost all of my employment experience overlapped, as in I was nearly always working 2 jobs at a time. I just basically documented work experience for the entire duration I have been certified as a paramedic. I did not document any of my EMT-B experience, and I did not have any periods of unemployment or self employment, so I can't help you with any advice on those issues.
As I understand it, your pay is calculated based on years that you have actually worked in whatever discipline you are being employed in. 6 years working as a paramedic, you get paid as a 6 year medic. 10 years as an EMT B and 6 years as a medic, I think you still get paid as a 6 year medic. That being said, the most important employment documentation is letters from where you were employed as a medic, as those are directly related to how much you get paid. If you are unable to prove you have 6 years experience as a medic when you arrive, I have a feeling they might re negotiate your contract and pay you for what you can prove...
Keep in mind these are all educated guesses on my part, and I am making these assumptions based on my experience with the SRCA recruitment department. Individual results may vary...
Also, I posted pics on my blog of the current aircraft I am flying in, if anyone is interested...