Dear Editor-in-Chief, or whoever asked the original question:
I think the choice will boil down to CentOS or Ubuntu, there is not much to separate both of these, but Ubuntu would be better choice in your case. The reasons being:
1. You want to do Photo-Editing:
If you are doing light editing, the native linux graphics software will do i.e., GIMP. But learning it would require some time depending on your learning curve. Though GIMP can be used for advanced editing, but I reckon you might be more familiar to Adobe Photoshop by now. You can setup Photoshop on linux using "Wine" which is a software to allow Windows apps on Linux. It is easier to set all this up on Ubuntu compared to CentOS or other Linux flavors. (PS: CentOS and RHEL are nearly identical).
Also, since you are probably having a high-end GPU like 1080Ti or 1070 at least, you would obviously want to make use of their computing power for Gfx Editing. Installing Nvidia or AMD drivers is also easier on Ubuntu, compared to others.
Nvidia Driver for 64-bit Linux:
http://www.nvidia.com/Download/driverResults.aspx/134859/en-us
Wine: https://www.winehq.org/
2. You want to use VPN (preferably OpenVPN):
VPN is quite easy on any Linux distro, so this is not much of a limiting factor. But on Ubuntu, you might find a nice third party GUI as well to manage it, besides the common terminal approach. You might want to read a good article from DigitalOcean on how to setup OpenVPN on ubuntu.
https://www.digitalocean.com/community/tutorials/how-to-set-up-an-openvpn-server-on-ubuntu-16-04
3. You want to Edit Code (HTML/JS):
Coding is not a hassle either. But the Editors on Linux distros, can require some getting used to. GEDIT is a good start, specially if you are coming from Windows. I have seen people recommend Vim and Emacs or even Nano, although in my opinion they require a bit more effort to become familiar with.
4. You want video conferencing (preferably Skype):
Skype has good support on Linux, which you can check on this page:
https://support.skype.com/en/faq/fa10328/what-are-the-system-requirements-for-skype
5. You want a Office365 complaint Email client:
Although there are many good email clients available for Linux, yet setting them up with Office365 is a problem-too-big. Even if you install the office365 app via Wine on linux, the results are far from perfect. Even Thunderbird (from Mozilla) is not a clear-cut answer here. Sorry, but that is how it is.
6. You want Web Browsing (Duh!):
I don't know what you mean by chromium here. If you are referring to ChromeOS, you can dual boot it with a Linux Distro, but just for Web Browsing, doesn't make sense.
And if you mean Chrome Browser, than in that case, its no problem. Some Distros come preinstalled with Mozilla Firefox, but given Chrome is mainstream browser, it is easy to install it on all Linux Distros.
The OTHER REASONS playing in favor of ubuntu are:
1. Superior GUI compared to other Linux Distros (clearly apart, and probably the biggest factor)
2. It is as close as you get to a Mainstream Linux Distro, all others have a higher ratio of Enterprise users.
3. Better support for various hardware devices, and a vibrant and helpful online community.
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I hope that helps you.
PS: I can sure use a free Toshiba SSD, given I have a tight PC budget. But shucks I'm not a US/CA citizen (I'm from Delhi, India) :/
I will leave my answer as it is, so it is helpful to anyone who requires it. Winning is not everything for me, but perhaps your 'friends' at Toshiba might change their mind about the rules
😀