Welcome!
I am no more athletic than you for sure (a little younger at 45 granted but the only real exercise I get is walking the dog at the weekend - and airsoft once a month). I too suffer from tinnitus but did you mean Agoraphobia or claustrophobia? I would have thought being agoraphobic would have stopped you being a wildlife photographer?
Anyhow, it sounds like you've made an informed decision regarding sniping which is the polar opposite of how most new (younger) players come to the long guns. The reason we try and discourage them is because they don't realise that they can't hit someone on the other side of game area or "no-scope" with an airsoft rifle and just how expensive sniping can get in terms of upgrades and the law of ever diminishing returns.
One word of warning though - sneaking about in the bushes bent double to hide from view wreaks havoc on your knees!
Have at it though, I'm sure you're going to enjoy yourself!