I'm just curious as to how far you intend to go with the shop function, as for Lordaeron when Brewfest trinkets were made available in Naxxramas through the shop, it hurt the progress of T7 massively, it was basically a "have your tanks buy the trinkets or be square for race of realm first".
What I will say though, is that if you enable Kara loot in T5 that's perfectly fine imo.
I'm just curious as a long term supporter since molten days.