Certain quality of life changes i could be fine with. Battle.net integration is expected. Color Blind Mode should be a guarantee. Guild Banks/Mailing upgrades. Auto Dismount. etc. i can live with these.
Transmog, LFD/LFR, Balance Changes, AoE loot, etc just don't belong in classic wow.
Transmog ruins the economy, especially for newer players.
LFD and LFR - i don't think i need to explain either of these. but if you want me to, ask.
Balance Changes - the problem with balance changes is people don't think about the entire aspect of the game. In Live a Ret Paladin has like 1/5th the toolkit of a Holy Paladin when ti comes to healing, and he can only use his heal like 4 times before being oom and it might heal him for 40% of his health total over that. in Vanilla they have access to the whole Shebang, and 2 Holy Lights will heal them to full. Combine this with Bubble and Dispells, if you gave Paladins the DPS we see a lot of them asking for on the forums, they would be utterly unstoppable.
AoE Looting only benefits two classes really. and has pvp implications.