KISS - Keep it super simple!
Thoughts about wikis in general
Today if you hear the term "wiki" most people at first think of Wikipedia. Indeed the success of Wikipedia as an encyclopedia written online by anybody did help a lot to make the wiki principle more wellknown and common. Having a look at mobiki you will see, that it is a totally different thing. It is intentionally much closer to the ideas of the original first wiki authors.
Maybe you are interested in the original thoughts of what a wiki is and what it's destinctive design principles had been. Although mobiki is thought as a personal content management system and not so much as a community based knowledge pool, many of the original design ideas fit very well. It is described by Ward as "The simplest online database that could possibly work."
It is ok, if you want more. But if you can't reach your goal with a wiki, you shouldn't morph a wiki into something, what is not in it's nature. Don't try to replace HTML with a simplified markup, which is not simple anymore! Get one of the good and free content management systems, which are much more full of features, and get lucky with it.
A wiki is more or less text-centric, a hypertext system. This means, that it is not a fixed and bound work with an index, hierarchical chapters, a glossar, page numbers etc... And in no way a single wiki page is something like that. A wiki has pages, which are connected by setting links to each other at positions in text, where it is appropriate. Therefore mobiki does not provide hierarchical headings for use on one page — you just automatically get the page title and sections on that page, as you can see here. If you ever feel, that you would need something more like that, it is a sure sign, that you should split your text in multiple pages in a clear and descriptive way.
Where does security start? Security here mostly means to enshure, that your website will not be abused, hacked, abused for sending spam mails and so on and that the text is kept, as it was written by the author. Really, for all the software we use day by day we are forced to trust the programmers, that the software is free of bugs and provides constant and undesturbed service, once installed. My own experience is, that this is often not the case. Some programmers resources are limited (as my own resources are too), some do not have enough profession to provide a good quality of software (as me possibly too) and some simply don't care.
So, after one of my installed forums was hacked a couple of times and my provider wrote me, that also my wordpress blog is endangered, because of some bot nets specialized in brute force attacks are on the way, I decided to write my own software and understand it fully by myself. If a software like mobiki is small enough, this is indeed possible and you should have a look at it yourself. The source should speak for itself, some comments will help and in the end there is the hope, that if you find some critical bugs or exploits, you will possibly inform me. It is open source.