Yep the 133 is size for weight "by the book".
If its to be used for what its built for; ie as a wave rider; then 'by the book' is probably the way to go.
As a 1 board quiver probably another good reason to go a bit bigger than a bit smaller. Extra deck area will increase bottom end a bit.
Every point you make - gusty; not too strong; adverse currents - all point towards the 133 being the better option for you.
My preference for the 131 is that I am pretty much just free-ride & often in flat water spots. If Im in the waves Im just playing with the lumps rather than 'surfing' the wave. No advantage in the extra size for this fun & games style and I found the 131 easier to throw around.
Surprising how much difference such a small size variation can make. The 131 felt like it fitted - the 133 felt big???
And gotta remember too that I can always pick any board I like anyday, any spot.

Theres gotta be some advantage to having a shop.