If I have a starting Agility of 10, is there any point in taking Action Boy? Or Bonus Move for that matter. Thanks

Action points aren't limited and extra action points are always good to have.

personally i find "Bonus Move" perk useless, on the other hand Action Boy is one of my favorite choices since you can really up your "shots per turn" especially if you have "Fast Shot" trait and are planning to pick "Bonus Rate of Fire" perk, for example you can shoot like 4 times/turn with the gauss rifle if you have both FS and BRoF, and if you have high critical chance you don't really even need to aim for high dmg.

another point is you can fire 2 or 3 bursts and reload on one turn (for example Bozar 5AP/burst and 2AP/reload)

As a new player, is there somewhere I can stash the stuff I don't want to carry, but don't want to get rid of because it might be handy?

as far as i can remember you can only stash stuff in your car, i guess you could try stuffing something in some easily accessable locker or something but i have no idea if everything stays there when you leave screen/area. i'd recommend giving everything extra to your companions if you have any and getting the car asap

Just a note here, as long as an object is in a container it's safe. If you leave it on the ground, it'll disappear eventually, but any container (car trunk included) will keep it forever. You can even use the car trunk for storage before you've gotten it running, which is convenient in the early game since the Den is pretty centralized for the low-level areas.

nice, thanks for the info