Just want to make sure, if I do the exams through the UK CAA, can I do the sim ride with another authority, or does it also have to be done with the UK folks?
Ask the caa you want to do the sim ride with.
Do all the European nations view the JAA ATPL the same regardless of the issuing country?
If you're talking about a jaa license, then yes. If you're just talking about the atpl-exams, then no, that would depend on the caa.