Hi, I'm a relative beginner to Linux and Ubuntu so try to keep any replies easy to read

Also, I apologise if this thread is in the wrong place, but it seemed the best place I could find.

I plan to set up an always-on file server/bittorrent client at home, using a lot of help from this guide:
http://ubuntuforums.org/showthread.php?t=1895084

I'd like the server to be as secure as possible without being beyond my capabilities to set up, and the security measures outlined in this tutorial seem to be as much as I'll need.

However, I plan to also route all of the server's internet traffic through a commercial VPN provider using OpenVPN for privacy and security issues.
What I'd like to know is, how does using a VPN in this way affect my ability to access the machine remotely?

I'd like to be able to control the server remotely from both inside and outside my home network, largely to access a GUI web interface or CLI for my chosen torrent client (probably either transmission or deluge) without compromising the VPN connection.

In other words, I'd like to be able to control the system remotely from outside my home, whilst ensuring that anyone else on the internet who connects to my server only sees the IP address provided by the VPN service.

Would this be achieved by simply setting the VPN service to forward certain ports that are being used for SSH access or the web interface of the bittorrent client or is there something else I'd need to do?

Apologies for the long-winded explanation but I just wanted to make myself as clear as possible.