[Forever_kaos]

1) IMO - Depends on the brand, but generally if it runs good I would run it till it breaks or you need to swap the spring out.

2)Too much, as others will probably say.
I do WW2 re-enacting, for the most part with airsoft weapons. All the kit and do-dads add up quick, especially if you want to do it highly authentic.
But by all means, I do play airsoft for fun with friends once and awhile, which you will learn can get "pricey".

Some gents will drop ~2-3K on a Systema PTW/FCC, add on mags and all that jazz, weapon gets expensive on it's own. Some throw on some nice night vision bits too, 2-3+K again. Top notch real deal gear, the dollars add up quick as heart beats! Hah.

Don't feel like you have to spend anything more then what you want. I've seen folks just love run around skirmishes. They buy decent boots, some midcaps, pouches to carry said midcaps and they're done. Not a care in the world for tac gear or anything of that sort.

I say get out with what you got, maybe a decent battery if need be or find out if the place has electricity you can borrow with your charger.
The more you go out, the more you will learn what is effective for you vs useless weight.