(1) Yep, easier to use rates of exchange published monthly from HMRC website as a source to translate euros to GBP
(2) Yes
(3)a loans cannot be expensed unless lucky enough for lendor to write off or write down the loan, then exceptional item in P&L.
(3)b cost of training. Training is a funny one. In summary, if profession related training was done pre-profession; then cannot claim. If during trade (eg: profesional development), then yes can claim.
There are companies out there with specific technical skills that accountancy and bookkeeping practices use, where there are internal knowledge gaps.
ps: this is not advise but a discussion, so I or my related parties are not liable for my response to your questions.