WOW, comprehensive reply.The update works great, I finally downloaded it and if you follow the steps everything works.
I don't know why the creator uploaded it to such a dubious repository that links to more and more sites. Anyway, you did something wrong. Try again following the instructions here:
You have a lot of questions. which no one - probably not even the creator - will know.
If you don't play directly on the official server, you will never, NEVER be sure of 100% functionality. However, during my tenure and tests of quant repacks, I have to say that overall azerothcore will probably be the best of all.
Azeroth core Zaicopix is just a repack of some zaicopix , a fan of warcraft who edits a pure azerothcore that is freely available to the public. You too can modify and script your own azerothcore here: https://www.azerothcore.org/
I personally prefer to spend my time testing and playing. So I don't do repacks even though I know the commands well, as well as the database.
Now for the questions:
1. I've gone through a lot of dungeon quests and raids and haven't found anything broken yet. Except for a few non-essential quests, like: https://www.wowhead.com/wotlk/quest=12227/doing-your-duty, which I'm sorry about, because it's a pretty funny quest . Things are completely in the database there, if you mean special card items.
2. I didn't find any big majority errors and even the ordinary quests in the open world run perfectly.
3. Yes, PVP multiplayer is playable and hard. After the update and working Alterac, I can say that it is an hourly slaughterhouse. Sometimes I think it's not even possible what bots do.
As for the quality of the repack. Yes wotlk is the best repack ever. I also miss some things, but more out of interest. For example, engineering stuff. Anyway, despite everything, I like Wotlk the most because of the story line.
The best way is to try and explore the world on your own. It takes a lot of time. I've been interested in this for almost 20 years and I had to figure out a lot of things myself... and sometimes it hurt
By the way, another good repack was from the Conan repacker. His server was exceptional because it used PLAYERbots, not NPCbots. It also used to reduce the HP of monsters in the dungeon, based on the number of players in the party. Unfortunately, he also got into NPCbots and canceled the old project. Zaicopx repack seems the best for me at the moment. If they set up all the BGs and Arenas it will probably be the best repack ever.
And Zaicopx could also respond. He simply farted the repack on the website and "died".
All the best.