#2 If you want folders so bad, add a label to a message, then archive. That’s all
your HD does. When you move a file from one folder to another, it just adds the new label, and removes the old. The “file” remains just a string of 1′s and 0′s on the platter.

#3 Ionut covered that fine.

#4 I don’t use GMail as my PIM, and therefore it’s fine for me. Gets the job done nicely. To each his own I guess there.

#5 If getting at your largest messages is that important to you (who cares about the 40 million small ones Then access your account with IMAP and a decent client (I use T-bird) and it’ll see the sizes and let you search/sort on them. Then you can act on them, and it’s reflected in your account. Honestly, doing this ONCE was all I needed to realize I was being too retentive and just forgot about it since.

Gmail will add an option to “move” an email to a certain label, combining labeling and archiving in a single step.

“But it does not provide the option of whitelisting an email address to ensure that certain important emails never go to the Spam folder.”

Add the email address to your contacts. There are some exceptions from this rule: http://mail.google.com/support/bin/answer.py?hl=en&answer=10514 , but it generally works.

“Gmail’s contact manager is quite ordinary and does not provide any advanced options such as merging contacts.”

It will.