Yes, search in Win10 can be hit-or-miss. If that method doesn't work, I use the Explorer search, but if I really want to find something, dir is the tool. But then I still have to figure out how to launch these universal apps
Did the other app tutorials help with the Store issue?
All other MSO pgms launch HTML links fine - right, it's just Outlook and only in recv'd mail - right?
It's not a ctrl-click the link thing is it?
Another member is going to be more help to you on Outlook (if they show up ), but I am enjoying the conversation and trying to help with other issues (the Store & Feedback) as they crop up.
I'll keep thinking about the issue, maybe search again - but you seem to have tried the low hanging fruit.
SFC didn't find anything, perhaps Dism will repair Outlook and the link association.
Open an elevated
Command Prompt (right click, Run as administrator
Enter the following command
Dism /Online /Cleanup-Image /RestoreHealth
Post if there are any errors on the screen after it runs.
Full tutorial: DISM - Repair Windows 10 Image - Windows 10 Forums
The only other thing I can think of is to install Outlook 2010 on top of what is installed or re-install it.