All answers I am about to give are based on me making a range of assumptions…
I would say for sure keep good bases with bad perks and blessings. Those can be swapped out without locks once your mastery is at high level.
For weapons with decent stats, you could use what seems like the new “enhance” mechanic to upgrade the weapon to higher base stats. The way I am seeing this as working as that you can enhance a 360 weapon to a 380 (final numbers may be different) via enhancing and before you do the new system will show like… faded bars to show you the potential as to how high the bars can go. So the random component is stat distribution but every single weapon in the game can be upgraded via enhancing to a max base total.
So is it worth holding on to? Hard to say without the preview. If it’s a low base total like 320 or something, it may not be worth the enhancing costs so it would be better to sell it or extract the blessings if you need em. Otherwise I would hold on to it in case the “final” version of the weapon has the stats you want.
Selling weapons in the new system also seems to give crafting resources vs just ordos so may also be better to hold onto for that unless you need em now.
I also have no idea if I mastery is blessing tier retroactive. If I have blessing A at tier 4 unlocked, but not tiers 1-3… do I get the same amount of mastery in the new system or only if I got the lower blessing tiers too? No idea on that one.
I feel pretty confident in saying your weapons won’t go away (CM said to keep your weapons). Blessings on your current weapons, if you didn’t extract them, won’t count towards mastery pretty sure, just the library. The weapon would still be usable even if you haven’t unlocked the blessing BUT it has a total mastery rank so you can’t use weapons that have high mastery (high stats and tiers of perks and blessings) so you may need to level that up before using the weapon.
My question would be on this point^. It mentions the weapon level here can only be as high as your mastery with a weapon so you can’t modify everything until max rank. I don’t know if this means if you can equip and use weapons with higher total value greater than what you can do with your mastery or if it’s just for changing things.
I could be very wrong about all of the above^