Yup, put the OTC qualification on the site, it will reassure people.
Bank transfer is a safe way of paying over frontiers without incurring high bank charges; there will always be some costs though with pound/euro transactions. Geld uberweissen is very common in Germany and Austria, and there are people like me that won't use Paypal. Give customers your IBAN and SWIFT numbers and they can transfer money direct to your account.
Copy/paste the text for your site into Microsoft Word and run the spell checker on it. Check on the use of apostrophes and hyphens too as word won't show up errors in their use. Plurals don't need an apostrophe.
You could do with some photos of pretty XC trails on your site.
The biggest put off is this:
Of course, your travel arrangements are entirely up to you, so if you're thinking of a shorter or longer break, we can provide information on the best way to go about organising it. We could tell you about each and every hotel in Kaprun, but there are so many good ones we could fill our web site completely on just that
Accommodation is a very important part of their holiday to most people. if you can act as an agent for local hotels and guest houses in need of summer business you can provide a more complete package and make some commission into the bargain.