I found 9 extensions in "troubleshooting". 3 exts are mine. 6 are not. delete y/n? ie i don't do twitter.
In "help", "troubleshooting", "extensions", I found 9 ext's. I put in 3. The other 6 are not from me. firstname.lastname@example.org email@example.com firstname.lastname@example.org email@example.com firstname.lastname@example.org email@example.com Are they necessary? Can they be deleted. If yes, how? I seldom, if ever, use the first 4 in the list.
Those look like search engines.
Type about:preferences#search<enter> in the address bar. You can select any search engine to be your default from here.
You can also remove any engine from here.
Yes, all those extensions are search engines like posted above. You can't remove them from the "Help -> Troubleshooting Information" page. The search engines you see listed are the ones that apply to your location (region) and you can manage them via "Options/Preferences -> Search".