I am unable to answer all your questions... as I wouldnt mind them being answered either... ill have a play my self later on.

re: "What I have just discovered :-( is that often this "instantaneous" email process takes several hours,"

I believe thats to do with your webhost or the end users email provider.... I have came across this when i signup for newsletters or forums... and i simply never get the email (confirmation email!!) or it takes around 24hrs to get to me.. either its the viewers email/isp or your webhost... i dont think much can be done.....

Warp.