So, to be clear, before I start looking up reports on the bugs forum, and cross-referencing with the Classic Not a Bug list, the following are what you are describing as clearly game breaking bugs that you believe fall into what can be definitely be called the “obvious” category and have been met with radio silence:
- vanish not working
- feign death not dropping combat
- mobs inappropriately aggroing on threat generating abilities used by players who aren’t in combat with them
- hunter pets losing happiness below zero
- druids getting mana burned in shapeshift
- execute/ferocious bite “eating” any rage/energy generated immediately after their usage
- grounding totem not working
- interrupts inappropriately triggering an additional global cooldown in addition to the spell lockout
- mind flay getting knocked back through PWS
- movement speeds being calculated based on WOD speed formula instead of Vanilla formula
- And others that have not been mentioned, so will be disregarded due to the nature of the question this is a direct answer to