Tax
As said above you can register voluntarily for VAT but if you turn over just over £61K you must be registered for VAT. As an FI I personally believe you are better not to be registered as you have to charge your customers VAT on top of what you want to earn. The reclaims are less than the lost business. Once you scale up your business then consider it.
You can claim anything necessary for your business. This includes a proportion of your property expenses if you work from home. If you add up all your start up costs you can claim any losses against your previous 4 years tax bills.
Just be carefull about IR 35 if you work for one flying club or at one airfield. Mr Inland Revenue disallowed £900 of travel expenses I claimed because they were to the same airfield and he considered it my primary place of business. However at the same time he allowed a computer I bought 5 years previously.
Your local tax office will actually send a small business tax advisor out to see you free of charge. They will tell you what oyu have to pay but not what you can claim. Visit your local enterprise council who will be more than pleased to help you.