Here's what I'd like to do. If you'd be so kind as to tell me if this is easy stuff with Limesurvey, I'd greatly appreciate it.

Limesurvey would pull a list of recipients from a feed.
Limesurvey sends unique URL to each recipient that will identify them. No login or filling out of user info needed. I will match unique URL with the results in my database.
Limesurvey would provide a feed of the unique ids and results.

What is meant with pull a list from a feed?
You can upload a recipients list via CSV import and generate invitations with tokens.
docs.limesurvey.org/Tokens&structure=Eng...tions+for+LimeSurvey
You can export response data in a few formats.

If you want automate the whole process you might be able to use the remote api
docs.limesurvey.org/RemoteControl to get this done.