yes, you'll need a Zotero account for data sync in any case. You'll also need a webDAV account, which is separate (and wouldn't be through Zotero). If you use Zotero's own storage, you obviously only need one account.
We have a Webdav in our server but it makes no sense to us to have an account to sync ... It seems that you'll get our personal datas which makes no sense to us.
Ok so I found out that you guys need us to create an api key to interact with your server. What information are you keeping ? How your are going to use it ? What is the purpose of this api creation ?
I'm not familiar enough with the custom set-up I link to to give you details, but there's certainly no technical requirement to create a Zotero account, no. They may have chosen to leave account creation on zotero.org in place because it's convenient. Any question on that, post to the appropriate thread on the zotero-dev list, e.g. https://groups.google.com/forum/#!topic/zotero-dev/6Rk8xr0XwO8 (Zotero provides no support for local dataserver installation, but the people who have them running are usually pretty good about responding)
(obviously that only applies for using Zotero sync or zotero.org. As I say above, the entirety of Zotero's code is open, so you can in theory replicate the full Zotero service locally and wouldn't need to interact with any Zotero servers ever).
You'll also need a webDAV account, which is separate (and wouldn't be through Zotero). If you use Zotero's own storage, you obviously only need one account.
http://git.27o.de/dataserver/about/Installation-Instructions-for-Debian-Wheezy.md
Regards
(Zotero provides no support for local dataserver installation, but the people who have them running are usually pretty good about responding)
API keys are used as they are for all REST APIs, i.e. to authenticate API requests. Zotero's privacy policy is at
https://www.zotero.org/support/terms/privacy
(obviously that only applies for using Zotero sync or zotero.org. As I say above, the entirety of Zotero's code is open, so you can in theory replicate the full Zotero service locally and wouldn't need to interact with any Zotero servers ever).