#9 is actually ammo pickups. if you look closely the match the ammo types that we see on the guns in the bottom right when switching weapons. They're simply ammo stations
I could take or leave the health bar over that one boss, I do agree that an option to turn that off would be nice although nit picky, maybe if like they need something over it make it just the nameplate like multiplayer.
From what I noticed at the upgrade screen the grapple seems to have an upgrade that recharges, so that it's not default that it reloads beyond the 3 time usage as we have in multiplayer but an upgrade choice.
I think they should ask you at the very start:turn on/off boss HP-NAME-highlight shields. I think it would solve that issue simply be able to turn them off at the start
To me it looks like different collectibles serve different purposes. Skulls are...well skulls, intel could be like terminals, cores are a currency, but the little circle thing could be vehicle parts or something for vehicle upgrades, maybe one of them is a weapon upgrade