Dan,
When you go to Wallop, you will be assessed for the duration of your visit, both by Directing Staff and Officers and SNCO's you will meet.
Your motivation for application for a Commission in the AAC will be probed. The AAC is not interested in Pilots with a Commission, they want Officers with Helicopters on their backs.
A contentious subject, but if you are driven only by a desire to fly, that might not be enough to get you through a year at RMAS, and to finish in the top third.
Be yourself.
Remember that the AAC wants an Officer with a broad range of skill sets, and a desire to lead. Have a long look at the future AAC career profile you are likely to lead, and realise that unless you specialise, you wont be flying for ever.
Ralph