Few Questions - Itemmall, Item-IDs, Cap-Edits, Community

Hi there,
I managed to set up my own server yesterday following the One-Click-Server Tutorial. Now I came across a few problems and it'd be great if someone would help me out with this.

1) Itemmall
I managed to create my own Itemmall (just with two Eidolon-Keys to see whether it works out), then I imported a premade Itemmall.sql by @yokohiro but when I tried reloading the Itemmall ingame, it said "Itemmall reload error". Also, Navicat gave me a notification "itemmall does not have a primary key". I then cleared the itemmall and since then I always get the "Itemmall reload error" ingame when I try to reload it.
How do I properly import an itemmall.sql file and make it work ingame?

2) Item-IDs
Is there a document or list somewhere where I can find Item-IDs (and Eidolon-Key-IDs etc.) and their ingame name, category etc.?

3) Cap-Edits
I noticed ingame that the cap for fragments is set to 30.000 but I somehow cannot hold more than 9999. How do I increase the caps for fragments or coins such as LP?

4) Community
Is there a Community Discord for people who work on AK-Projects to help each other out?
If so, I'd be happy to join!

Thank you very much in advance :)