PrinceShroob

Y'all do know that exported face textures are just tints and the mesh is just headparts, right? New textures shouldn't affect anything, else they'd have needed to export facegen with the HD texture pack.

Of course it causes the gray-face "bug"; if an actor's exported facegen and their current headparts do not match, then you see a gray face. Changing an actor's race to make them a vampire is a method Bethesda rejected using in Dawnguard precisely because of this problem. Changing an actor's race to a vampire race will override their eyes (and head, with Dawnguard); this is necessary so that changing the player's appearance works properly. This causes a mismatch with their exported facegen. Whatever mod you're using should do what Dawnguard does instead: using an alias to apply vampire keywords and spells and using SetEyeTexture() to change the actor's eyes.

It's not a bug. It seems to be intentional, I presume because Vampire Lord is already very strong without having an essential, powerful follower accompanying you.

Because the follower hunting bow is no longer unplayable, followers consume arrows normally. However, you can now replace the hunting bow with a stronger bow.

That quote in context seems to be implying that you can use the Creation Kit on the PS4, but can't upload extra assets to use.

You assign a new name through an alias; assuming Kvenel is actually in the alias and the quest is running, if he's not being renamed, then he was probably in an alias errantly flagged as "uses stored text," and the most likely culprit for that is a Companions quest.

"Beyond a reasonable doubt" is the standard of evidence for a criminal trial, which may be a life-or-death decision. I don't think such a standard is warranted when talking about a computer game.

Unless you're alleging that this issue is a microcosm for a larger problem, I don't really understand why you're so hung up on it. Nevertheless: with regard to the Custom Fit perk, several NPCs have the incorrect full set perk assigned for their armor skill; thus, Isran's case is not indicative of intent, especially since he doesn't wear a full set, anyway. He has perks for several weapon types in which he is not skilled, yet is not a follower and never receives another weapon, so those perks are not indicative of intent, either. He had no armor skills whatsoever before the patch fixed TrainerHeavyArmorMaster for Farkas. Isran orders the attack on the castle, so, yes, it is premeditated, and furthermore he's so paranoid that he'd want to be protected at all times.

Isran participates in the battle at Castle Volkihar during "Kindred Judgment" if you've sided with the Dawnguard, and you fight him yourself during "Destroying the Dawnguard" if you've sided with the Volkihar. It is generally accepted that NPCs are intended to wear armor they are proficient in using, more so if they participate in combat during a quest. In this case, Isran shares his class with Farkas, so his class couldn't be changed to match his worn gear, unlike, say, Aela the Huntress, who is the only user of her class. Israel's perks are a mess of dropped concepts and don't correlate with his gear necessarily, but he does have the Tower of Strength perk, which requires him to wear heavy armor. He also has the Custom Fit perk, which would give him a higher armor rating if wearing all light armor, but he doesn't wear a helmet so its effect is null.

Possibly the constantly-cycling Companions radiant quests plus "uses stored text" on an actor alias. It prevents any name replacement from working on that actor afterwards.

Yes, I've noticed that, but did not correct the audio due to a dearth of suitable samples.

The game is probably rounding the weapon damage down because your Blunt skill and Strength aren't high enough to see a larger difference in the weapons' damage.

-1 rank is used for dialogue recording; the actor is considered to be both in and not in a faction, so that all dialogue is exported for recording. Lydia actually should have -1 rank in PotentialMarriageFaction, as she's only supposed to be available if the player buys Breezehome, and a script adds her to the faction on purchase.