It does seem that every time a good point is made by an REer the FEers ignore it or derail the thread.
I've tried that before, too. Almost ironically, it was derailed, though since that happened after it was considered a 'rant', I guess that makes a kind of sense.
http://www.theflatearthsociety.org/forum/index.php/topic,59326.msg1520019.html#msg1520019
You did get a bit ranty
Back to the original point though, your point is valid and has been brought up before but they don't see the contradiction in these 2 positions.
1: The earth looks flat at a local level therefore it is flat.
2: the sun looks like it's going below the horizon therefore it's a complex arrangement of perspective, atmospheric opacity and maybe bendy light.
Most Flat Earthers hold 1 thing sacrosanct and that is "The Earth is Flat" everything else has to fit in with this view. It's one of the reasons why there are so many "Theories" flying around the site. I also think the multiple theories is a kind of smoke screen as they can always refer to another that might answer your question.