Yes and yes.
I have just tried startingPhotoshop and I don't get to the Welcome screen as I get a message that it can't start as there are some missing files. Have restored Windows to the day before I started my first uninstall of PrE but that didn't help.
I will now try a reinstall of PSE as well and that should fix it the CAHeadless issue I believe. I have copied My Catalog folder to Desktop and hope that I can add this back after the reinstall and that will overcome my fear of losing all my tag info??