Dear Mel,
i am here in dubai from many more then 5 years...
regarding writing you MOH exam it is MCQs and most of questions are clinical based...
so if you have some exp it shouldn't be a problem...
as long as working as Cardio respiratory in the hospitals under MOH you can work but in dubai govt sectors this is done by Respiratory therapist
If you need any futher information you can write to me..
Jani