I tried to install the wordpress script (clean server, just installed it), I got this:
PHP module mysql is required ..
Module is not available even after installation!
I checked, module is installed and enabled.
edit: funny thing, I tried to install on test.example.com That's where I tried to installed vtiger and it failed. But when I tried on example.com, I could install wordpress. That's not the first time I notice this, if I try to install a script and something goes wrong, many scripts will fail to install later in this domain, I have to delete it (that's why I try all on test noe, because I know it will get fucked up eventually).
I suggest you try all your scripts with Ubuntu 14.04, not all work (and I don't really have time to do it now)