This may sound like a bizarre question, but I've been noticing some oddities recently that don't make sense.

I've got a character with 142 mods and ~130 hours. I've had a stable mod list since the start, though I've updated a few of the mods.

Some examples:

After the high res texture packs were updated (so I did add the new texture pack and the unofficial patch), I started to see textures appear and disappear. If I entered and exited the tavern in Rorikstead for example, sometimes a texture (or several) would be missing from the interior. I checked this out multiple times, without reloading, and textures appeared to toggle. (This is a possible incompatibility with the old HQ texture pack fix, but it's odd that re-entering the inn would have different results each time.)

The values on enchanted equipment, like reduced magic costs, sometimes change between loads. This is without corresponding changes to plugins or plugin order.

At least one NPC randomly changes headgear. She's a Blade, and my house steward. Sometimes she wears her default headgear, sometimes she wears her Blades helmet, and sometimes she wears the headgear I gave her. This is great, in a way, but it makes me question if Skyrim is correctly handling it's records.

So my question is: is Skyrim really handling it's records in a deterministic way, or is there some arcane web of side effects between saves and plugins that results in semi-random behavior?