Don't denigrate Spanish. In the short term it may have no obvious utility. In the longer term it would suit you to international postings either at a NATO HQ or in an International HQ where the Spanish Air Force is also deployed. It would also open up embassy jobs in the distant future.
As for flight simulator, I can't see why that would be a hindrance.
"What have you done to further your interests in a career in the Royal Air Force?"
I am surprised no one has told you to trawl through the sticky at the top of the page. Please do that too.