The deal is that WHS is different than other OSes. If they install other addins then it usually some for some sort of functionality and the added perk is everything is very easy to install/uninstall. So remove what you don't use, but I wouldn't erase the addins. They might come in handy later.
For remote access, it's just a secure website (with your private domain name) so I doubt it's blocked unless work uses a whitelist for sites that are permissible. The browser will need to be IE (or Maxthon) though. Firefox doesn't give you the remote access features (just directory browsing of your shared folders). I use a Maxthon2 for access. It has the remote access plugins built in. It's portable so it doesn't need to be installed and I can use it from my flashdrive.
The backup and sharing is very nice. The backup I don't even think about. It's just there. My main hard drive dies last week and my new one should be arriving today. I'm very excited about how painless I think the procedure will be.
My system is not an HP. (I've just read a lot about them.) I turned my old desktop into our WHS. It's a P4, 2.8 GHz with either 512 or 1GB or RAM. I have 4TB of space (1 1TB and 2 1.5TB drives). I couldn't be happier with it.
One other thought for you. I actually don't work with date files on the server. I have my wife work with all her files (pictures, docs, etc) on her computer and then I have them backed up to her User folder every hour with a Sync program. I find that to be less confusing for her. She just works with things like she's always been used to and if we need to get to something remotely it's there.
I do the same thing with my GBPVR drive. I have one drive on my main machine with all my GBPVR recordings. It is not backed up by the server because I didn't want to keep copies of each and every show on my server for 6 months. So I have that drive set to ignore by the server. But then I run a daily backup of that drive to my Recordings folder on my server so that they are also backed up and servable. (I use SyncBack for all of this.)
One other thing I like about the remote access is that Microsoft provides the website for you and automatically redirects things so you don't have to apply (and pay extra for) a static IP address from your ISP. This way your server is always available. Just make sure you have a strong password for it.
Here's the list of plugins I use: WHSClamAV, Add-In Central, Disk Management, Client PC Information, Grid Junction, SMART drive monitor, P80, Remote Alert, Toolkit, Whiist, Customizer, and WHSBDBB.
Some good sites are: