A: This web app was made for Helldivers who have unlocked all stratagems (and ideally, equipment) and are looking for a fun way to spice up their dives.
A: You can toggle these items off in the Options menu. If you don't have the items, you won't roll them.
A: In the Options menu, in the Randomizer Settings tab, you will be able to customize the randomizer.
A: Feel free to choose a different booster than the one you have rolled. I don't make the rules, I just make the tools!
A: That wouldn't be very democratic, now would it?