General questions regarding ISPConfig setup

[FXT]

I am planning on setting up a server as securely as possible, given that I have to use Ubuntu 6.06 Server LTS and Joomla! on a site.

This server will be running in a VMWare virtual machine. It will later on be required to host more sites, mostly small experimental/static stuff for me and a close friend.

My plan is to use ISPConfig and create a reseller, who will have both me and my friend as clients.
If I understand correctly, the reseller will create the sites via the ISPConfig interface, and we as clients will then fill them with content via FTP. Easy administration, and no way to screw with the other sites that way. I have heard that this would be overkill, but i would like the expandability, and learning to do this is a good idea IMO.
Does this setup (reseller->clients) make sense?

Can this be done behind a router doing NAT, with only relevant ports being forwarded?
I have several *.dyndns.org domains pointing to my public IP, and would like them all hosted on this VM with its fixed local IP.
Is it possible to send mail from these domains, like user@asdf.dyndns.org?
Should I even bother with mail, given that this is a private connection?

I have been using the relevant "Perfect Setup" and it has been a great help combined with the info on these forums (thank you!).

One part I am not sure about in that Perfect Setup is the fact that normal FTP is used. I have enabled TLS for ProFTPd on one version of the server VM (approaching twelve different ones now!), and it works like a charm on the LAN. The NAT router is screwing things up, though, and I am not learned enough to find a way around that.Also I'm not willing to put the VM into this cheap router's DMZ.
Is there a way to do this, and more importantly, will it work with ISPConfig?
Is there a way of using SCP to work with ISPCOnfig?

I have been asking questions in another thread, which has made me reconsider some of my earlier plans, and hope that more than one thread is no problem.
I'm afraid it's many questions once again, I hope someone can answer them.