[Angelox]

Heres a few general and "exceptions" statement;
First, make all NPC's able to see through Undead;

UPDATE npc_types SET see_invis=0, see_invis_undead=1, see_hide=0, see_improved_hide=0;

Next, fix the undead to see invis, and not invis_undead;

UPDATE npc_types SET see_invis=1, see_invis_undead=0, see_hide=1, see_improved_hide=0 where bodytype=3 or bodytype=8;

Since usually, a named mob can see through anything, and a lot of named mobs start with an "#";

UPDATE npc_types SET see_invis=1, see_invis_undead=1, see_hide=1, see_improved_hide=1 WHERE name REGEXP "#";

Now you have a better general status on what sees what throughout the game. This isn't perfect, but is a start and needs more work.

exceptions;
I was just running to Dreadlands from FV and noticed the spiders couldn't see me with invis on. this is not the way it is- Spiders in Dreadlands and FV will see an whoop your arse. I remember many times getting screwed by the spiders, while on my way to Dreadlands on a CR.
So this will fix that;

UPDATE npc_types SET see_invis=1, see_invis_undead=1, see_hide=0, see_improved_hide=0 WHERE name REGEXP "a_drachnid" AND (ID>=84000 AND ID<=84999);
UPDATE npc_types SET see_invis=1, see_invis_undead=1, see_hide=0, see_improved_hide=0 WHERE name REGEXP "a_drachnid" AND (ID>=86000 AND ID<=86999);

If any of you know of more exceptions (like the spiders) or have more ideas, please post here either the fix, or just post it and I'll make the fix.