Various points and thoughts:

BA don't fly to ABZ any more from BHX, not since they sold it all to FlyBe.

You can check the airports at which Priority Pass have lounges on their website.

If you can cope with German, you can check FHR rates on this website: http://amex.start.de/classes/smp.pro...mer_id=amex_cc, and click 'Hotel suchen' on the left and take it from there. Find the FHR hotels from the Amex website, and then look them up on the German one. Note that outside the USA, the FHR rate is often more expensive than the cheapest alternative (i.e. you pay extra for the amenity / upgrade potential). Nevertheless some of the FHRs represent very good deals. See the Amex forum here.

Being in F will give you all the status you need on a BA flight - apart from being able to pre-seat yourself into either of the front two seats. (Which is one benefit of booking an F award rather than CW - cannot preseat at all before 24 hours to go without status for a CW award.)

Your Plat Charge Card will be of no value whatsoever on BA. Get out of your head this instant any idea that just waving it at people has any measurable effect. (It does have a use on bmi though - the card itself gets you lounge access there, as with Eurostar.)

Timing of the 241 voucher is everything with Amex. E.g. if you want to travel in the summer, you need to be able to trigger the voucher in August or thereabouts. It is only valid for 365 days after issue, travel must begin by that time, and if you want the best award availability for many routes you need to be booking at a year's notice. If your Amex year starts too late (e.g. June) this can pose spending challenges. If your year starts too early, you have to hold back on spending, wasting some of the card potential. So choose carefully the time that you apply for the card.