Very compatible. It may not run VB scripts on the file, but you will have multiple sheets, charts, and most of the formulas. This goes for Microsoft Word as well. They are not 100% compatible but work fine.

To transfer data you simply need ActiveSync installed. You can then (on your PC) use File Explorer and see the Pocket PC (any Pocket PC) as anothe drive. But only if you have ActiveSync already installed (it's not like a USB memory key that will work in any PC).

Alternatively you can use Wi-Fi on the i-mate and browse shard folders on your PC, or send files from your PC via Bluetooth.

Yes, it can be used as a modem for a laptop or desktop, via Bluetooth, infrared or USB.

The emal is configurable and you can set limits for the download size.