Please no.  The thing I hate more than anything else is to type a URL 
and then have it automatically hyperlinked (or converted or 
auto-corrected or whatever).
I don't understand your complaint.  Either the browser is wrapping the 
line or ckeditor (the HTML editor) is.  We control neither.  And 
neither is relevant ... since its the sending output that is all that 
matters (and we never add spaces/line breaks unless explicitly added 
by the user).

There is absolutely no guarantee that what you see on the screen is 
how a user will view the message, so I guess I'm not seeing the big 
concern here.
A paste will happen wherever the cursor is.  I have never seen otherwise.
This is all available in the ckeditor image menu/button.
There is nothing we can do about this.  This is a browser/javascript 
security issue.  You obviously can't automatically transfer things 
from your clipboard to the browser window without opening the world's 
most giant security hole.

1. ALL URLs and E-Mail addresses should become hyperlinks by default.   
PERIOD.  Do it the way Microsoft WORD does it, and note that WORD 
isn't even an internet application like Horde is.  DON'T MAKE ME DO 
ANYTHING TO CONVERT URL text into ACTUAL HYPERLINKS.  I suggest using 
the Microsoft standard of CtrlK to invoke the hyperlink dialogue 
(Thunderbird developers should do the same).

2.  When I go through the annoying process of converting a URL into a 
Hyperlink, then continue typing on that line or hit Enter to make a 
new line, the hyperlinking continues into the subsequent text/line.   
THIS IS A BUG.  FIX IT.  When the user creates a hyperlink from text 
or a URL, the very next character or line after it should NOT become 
part of the hyperlink.  Furthermore, once the user types in a URL, the 
very next whitespace or other character not allowed in a URL should 
trigger a built-in mechanism to convert the URL to a hyperlink.
3.  PASTING from some other document or web page into an email  reply 
is KLUGEY.  Often the paste doesn't happen at all.  Furthermore the 
paste causes an auto jump to the bottom of a document or page, and I 
have to scroll back up to the insert point to continue typing there.   
FIX this.  All pastes should happen INSTANTLY in the exact insert 
point (cursor location), and the insertion point and area displayed 
should not change except to show the pasted item.

4.  Offer a switch to enable all pasting of images to be right wrap, 
left wrap, alternating from the previous image placement, or inline.   
Handling of graphic insertions is KLUGEY.  Ctrl-V or right click paste 
should suffice without any additional dialogue box.