Happy to help.
Most of the Kings Fall raid weapons are bad, especially the AR, HC, RL and Fusion. You can safely delete them, not even worth collecting.
For others you have to know the rolls and perks, can't say otherwise.
Also, no reason to keep Y1 versions of exotics if you have the Y2 ones.
Cannot tell without seeing perks.
Google the perks and see if you like the sound of them. Try out the weapons and see if you like how they feel.
There are tonnes of reviews of perks and weapons online that will let you know which are good for PvE and PvE respectively.
Thanks for the info!
What about the consumables and materials?