As a reality check....Yes, as others posted above, W7 can be successfully run; however, if you are regularly dealing with very critical data stored on your main drive, regularly use banking and/or investment sites, retirement funds, etc. your exposure to hacking is far greater than with current OS's. IOW...if your financial situation depends on what you have on your SSD drive it could be a major hit on your life. This goes double-especially if a user regularly visits dodgy websites (especially porn), small, relatively unknown retail websites, receive a lot of spam email, especially if running a local client email app, and so on, the exposure danger jumps exponentially.
Just a fact of digital life.
I understand the OP covered these contingencies in the initial post, but I thought it would bear repeating.