You should really use SQLite! You will either end up with an ad hoc, informally-specified, bug-ridden, slow implementation of half of SQLite ... or, you will fail to even attempt the features that SQLite gives you - such as locking and dealing with concurrency - and you will have bugs. For example, you use file_put_contents. See this comment: http://www.php.net/manual/en/function.file-put-contents.php#... Please don'…
A blogging platform for personal use is not magic. Avoiding things like concurrency problems in small platforms like this is often trivial. Personally I also use a flat file blogging platform, and I explicitly rejected putting stuff in a database because I want to be able to edit the articles with emacs and check them into a git repository. Concurrency in my case is a non-issue because, well, there's only one of me.…
This project as it stands, quite frankly, looks like the worst of both worlds.