Definitely, the installation of mod_mono is separate completely from the installation of apache.
If I understand you correctly you already have apache2 installed and the main part of mono installed so you only need to install mod_mono and configure your site to use it?
The link in your post seems to be about compiling mono from source code not about installing from packages but you say Add/Remove which sounds like you are installing from packages using synaptic package manager? So I'm a little confused about where you're at and what you are asking. I would not think that the install of apache2 would in any way be combined with the install of mod_mono even using a package manager.
I've mostly been working with Suse which has a little different apache configuration than other distros in that the virutal host files are split out from the main config file and processed using include statements. Wish I could be more help but I'm not sure on Ubuntu. Maybe someone else can offer some good advice.
I'd be glad to email you a bash script that I use to get the parts of mono from svn that I build on Suse. Its basically libgdiplus which I'm not sure you need but I've been building it, mono, xsp, mod_mono, in that order.
so in detail, to build mono and install mod_mono after getting the files from svn I do
then you have to configure your virtual directory in apache. There are also .webapp files for configuring mod_mono. I'd be glad to send you sample files from my demo server configuration.
I learned how to compile mono from Paul Johnson's site
. He also has a script you can download to automate the whole process. I made my own script using a subset of his since I'm only doing web stuff.
Hope it helps,