Upload speed and archive bit...

I have a few question about ATI 2012 Online backup :
First, let me explain what I am doing :
Now what I did is a backup of My documents. Since it's so large that it will exceed the total numbers of Gigs upload per month I am allowed by my Internet provider, I am doing this folder by folder. Because your Online backup does not allow more then 1 Online backup per computer, what I did is that I edited each time my Online backup called "Data-Compositions-Score" by removing each time from the "Source" pane in "Edit backup settings" what has been backed up successfully (unchecked previously backed up directories) and replace it by a new un-backed folder so it wont start back complete backup each time. In the backup settings, I have set to: not to erase the previous backups (set to 99 versions) and set the priority to normal, low always crash and the backup wont start back where it was previously (that's a gigs consuming concern). I have set also the band speed limits to 80KPS at 2/3 of my upload speed limit of 1 Mbps. This allows me to continue working with Internet.
Three questions :
-How come that for a 1 gig upload at 1 Mbps speed, the time for it should be 2H29min 31.5 sec or at 2/3 of that speed (80Kbps) it should be around 3h45min and ATI does it at normal priority, in more the 30 hours ?
- I know that if I did complete My documents (130 gigs) I would have been able to have incremental backup but since the Initial is very large in size, it would have probably crashed somewhere (all large attempts have failed), even with success, I would have been using in excess upload limits with a considerable charge for it by Internet provider, and it would have prevent the start of all other LOCAL ATI backups for a very long period of time. In my method, If I succeed in backing up all my material, folder by folder, in a multiple steps backup, will I be able to select all of "My documents" at the end of the process and see that ATI will makes a backup of only the changed files since the first initial step backup?
-Finally, I want to know how ATI process files, to know how the files are changed and needs to be backed up? If it's resetting the archive bit on them, then if another incremental or differential LOCAL ATI backup is done after the Online backup of the same material, it wont be able to backup it up locally because the archive bit as been reset by the Online backup and will see it has already backed up. Could you describe for me the process and how I can be sure of backing up Online and locally?
Thanks in advance,
Claude Lassonde