XWiki setup and configuration issues

When a brand new user wants to use (not standalone) XWiki, there are too many things either hidden somewhere in documentation or skipped. It could be seen from mailing lists also: same questions are raised from time to time.
So, it would be very useful to help users from the very beginning, taking in mind, that not all of them are IT professionals.

To save time for those users it worth to cover following:

• Minimal/Optimal hardware requirements to run XWiki more or less seamless
• Minimal/Optimal parameters for JVM to run XWiki
• Minimal/Optimal configuration parametrs for at least MySQL to make it tuned for XWiki search engines. It looks not obvious at first sight.
• Necessary changes in Tomcat's configuration to run XWiki seamless. For example, very "simple" solution to put XWiki as DEFAULT application in Tomcat comes out as a headache (because XWiki needs /xwiki in URLs and Tomcat's documentation is almost useless in this case). Apache/Nginx typical configuration examples will save huge amount of time for XWiki followers.
• Make some xwiki.cfg parameters more clear to understand and to tune. For example, recommended values for minimal/optimal harware and/or software settings.
• XWiki setup: indexes setup, general recomendations on site security, necessity of manual open/save under user with programming rights nearly every page with scripts etc. It also not obvious from documentation. It's very annoying, when it should work, but it doesn't as described.

I don't suggest to "copypaste" Apache/MySQL/Tomcat/Nginx's documentation into XWiki's, but it's worth to make KEY points of the setup process more clear especially for brand new users.