Fully warded players en-masse are known to impact server performance, so lets play the devil's advocate and identify the most visually important wards (strictly spells that have permanent visual effects on a character for its duration) to, in theory, make performance smoother.
Visual effects to keep:
+Concealment (Imp. Invis, Ghostly Visage) - so you know why you keep missing and a little bit of WYSIWYG.
+Freedom of Movement - so players don't waste an action on a spell another entity is immune to.
+Aura Shields (Acid Sheath, Aura VS Alignment, etc) - so we know why we're hitting ourselves.
+Spell Mantle - visual feedback for spellcasters that indicates why their spell failed.
+Shadow Shield - 5 spells in one, important to keep track of.
+Divine Favour - important cleric spell which indicates when they're likely going to be doing high damage (also not a spell that lasts real-life hours).
+See Invis/True Seeing - important to know for stealthers.
+Lesser Mind Blank - so players don't waste an action on a spell another entity is immune to.
Visual effects to remove:
+Energy Buffer - good to know for spellcasters but I'm economising and this ward would be destroyed by end-game spellcasters pretty quick.
+Stoneskin - most don't use this because it looks hideous and is almost always quickly removed. There is also a sound effect that indicates when your hitting someone with Stoneskin.
+Protection Against Alignment - a ward everyone can assume has active at all times, redundant (also plays a wind-chime sound effect).
+Shield - scourge of outfits and everyone has this active, redundant.
+Epic Mage Armour - don't think this is dispellable so no reason why this wouldn't be active at all times, redundant.
+Good Hope - I think this has a vfx, not needed if it does.
+Spell Resist - at end-game I feel like everyone has access to spell resistance either through this spell or an item, redundant.
+Whatever that blue ward that appears on the floor like FoM, that can go.
If I missed a ward it's probably redundant.