Hello dredknight. It was almost a year from your last patch for vanilla 3.1 version. There are still some small and big bugs in the game, here some of them.
1) Luck Of The Barbarian - always gives 5% "Magic Proof" and doesn't scale with any "Luck".
2) Kragh - when press "Wait" before battle start, can use "Spellbook" instead of his "Hero Attack".
3) Fiery Wrath - don't work with "Ballista" even without "Flaming Arrows" skill.
4) Master of Earthblood - doesn't give "Earthquake" +4 "Spellpower" as intended.
5) Protection - I heard, that sometimes mathematical rounding decreases "Magic Damage" for 14% instead of 15%.
6) Weakening Strike - always apply "Basic Suffering" and doesn't scale with "Advanced" or "Expert" levels.
7) Fire Wall - when any creature gets "Dismoral" it takes no damage from "Fire Wall".
8) Goblin witch-doctor - after use "Defile Magic" on a hero and that hero, with low mana, cast expensive "Spell", he can go under -1 or less mana and can't cast "Free Spells" for 0 mana, like "Divine Guidance" etc.
9) Fortuitous Sanctuary - when it's monday, it gives +3 "Attack" but have no effect on "Ballista".
10) Treeborn Quiver - when "Poltergeist" use "Steal Ammunition" on any archer with low ammo, that ammo could be zero, ignores artefact bonus.
11) Fog Veil - doesn't work on "Balista". It could, because "Balista" is a "Shooter" and also gain bonus from "Archery".
12) Antimagic - Vampire prince can use "Torpor" on unit with "Antimagic". It's a creature ability, not a spell, but I think so strong spell couldn't be countered so easy.
13) Antimagic - Succubus seducercan can use "Seduction" on unit with "Antimagic".
14) Phantom forces - Vampires could "Life Drain" from "Phantom forces" creatures.
15) Phantom forces - Wolf casted by "Phantom forces" could use "Howl" to summon more Wolfs.
16) Untamed cyclops - when hitting castle wall and attacking with "Luck", no double damage done too that wall.
17) Ghost - Bloodeyed cyclops can apply "Evil-eye" even when "Miss" hit to a Ghost. Blackbear rider can use "Paw Strike" even when "Miss" hit and that Ghost doesn't "Counterattack".
18) Druid elder - no grade Druid has more health than Druid elder: 34 > 33. High druid also have 34 health points. It's controversial one, but in my point of view, Druid elder also must have the same number.
Summary: It's OK if you think, that some of this points are not bugs at all. Just want to hear your thoughts.