If traveling is your priority, do that.
If getting some decent learning and experience in a work situation is your priority, do that.
The opportunity here is limited by your summer timescales. Most places would want a long term commitment to the work they are doing – not a summer tourist. Can you do a full year out?
I’m not sure the two a particularly compatible unless you do longer, or simply take a job – certainly in a way the forces may see as relevant.
Yep, agree with that. Any leadership opportunity you could put together whilst travelling short term like that would be pretty fabricated and the AIB (or Army/Air force equivalent) are not daft.
You’d be better off staying back in the UK and doing something selfless or turning your travelling into an expedition. Something single minded and a bit rugged that demonstrates fortitude, independence and ability to adapt and innovate. Anything with a whiff of ‘gap yar’ will be discounted.