Any 20inch forks will fit.
BMX bikes all have the same size (20") wheels, so they're very similar in size. Doesn't matter that much as they are mainly ridden standing up anyhow.
That's a BMX, and there's not a lot of difference between forks for those. AS long as you get the correct steerer tube length, any BMx fork would give you a rideable bike.
Yes.
i am 14 going on 15, im 5''7' height and 9.5 stone in weight and i have an United Recruit RN1 2011 BMX which weighs 25.5 pounds, i am relatively strong for my size, not MEGA strong but slightly stronger then average and my BMX is perfect (FOR ME) ^_^* but remember it all depends on your size ,weight and strength! E.g. Weak Guy + Lighter BMX = BETTER :) Hope This Helps!
The forks go through the head tube and headset, the stem anchors the fork and then the bars attach to the stem, so the answer is the fork and stem.
That is very light for a bmx, 25lbs is average
the fork gyro (if have) and stem and mostly important the headset
Bmx's don't come in sizes. They are all one size.
what ever size fits them for their intended uses.
Depends on what's already on there, what's available, and how much clearance the bike has at the fork and frame.
BMX bikes pretty much all have 20"wheels, which makes all frames very similar in size. On top of that BMX is almost entirely ridden standing up, so bike size doesn't matter as much as it does for road riding for instance.