Trailer Inconsistency...Weapon + Levels

Could also scale like gear in elder scrolls online, maybe?

Or perhaps like in destiny where light level or attack rating on gear is what actually increases your character level

In destiny, a level 39 player won't hit level 40 until all gear slots are equipped with at least level 40 items. The game determines level by averaging out all of your gear.

I wouldn't worry about it since devs often cheat shit like that for trailers.

Well first exploitation is that we see a scripted trailer with dev in cheat mod (they do one shot everything). she does use a shotgun then use a sniper, the weapon just change skin when they come near the "dungeon" they need for xp.

Now for the level 35 : once again it may be scripted. However it may not be a level requirement to wear the item but an indication on the relative power of the weapon.

In WOW, gear have ilvl which is independent of the the required level to get those gear. They add in the last expansion a system that allow daily quest to give you equipment accoding to your current average ilvl. Maybe it is the same thing here, now that she is level 30+ she may gain of a higher ilvl when she roll for them. A way to ensure the equipment you get is not low level crap.

The game was just announced and is not going out until a long time. You can't expect a definitive answer on some aspect that can still be in discussion.

No man's sky did...though