Hi
1 - We cannot provide support for the content of your .htaccess, as this is related to your server config and your requirements, and not to sh404SEF.
2 -
404 report screen 2 shows one page of graphics of the 50+ images scattered throughout the website. I get all of these every week when I clear out the 404 report.
Those are regular 404 pages. They totally look like relative links (ie they should be absolute, relative links indeed generates 404).
As they are not marked as "Internal", it means they are requests from external crawlers or bookmarks (though that's not 100% sure, as referrer indication is not entirely reliable). You can click on the "Details" link to get a bit more information, notably referrer if any, and IP address of the requester. That might give you some information as to where those are coming from, and then maybe fix them.
3 -
I don't want to have to delete these line items week after week after week. Please make it do I can ignore them or they don't show up at all.
I don't see anything within the realm of sh404SEF that could do anything like that. Our purpose is exactly the opposite: record all 404 and make them available. We have no features similar to that and don't plan on adding any such thing.
I see 2 ways of improving your situation with respect to this problem:
A - use your .htaccess file to block those images, so that they don't reach Joomla (and in turn be recorded by sh404SEF).
which I set my .htaccess file to prevent hotlinking
if so, this is not working: those images are not blocked by your .htaccess, they do reach your Joomla site.
B - Just forget about it: let them be there, and once in a while purge 404 records.
4 - Tel: links. Your 404_report_screen_1 helped me understand better. Those tel: links are not recognized by some browsers, or the browsers of some visitors do not have an associated app to open tel: links on desktop, and so the browser just send the link to the Joomla sites, which of course trigger a 404, as it should. Another possibility is also crawlsers (not Google or Bing, but smaller crawlers). If you google for that problem, you'll find many people with it. Solutions are usually to not show the link when on desktop, but instead the raw number, as text .
Rgds