2. Yes.

3.IE version is just different from the normal version in terms of buttons. One-click Internet access is the same as the mobile customized version.

The installed software is just different. It can be downloaded from Saipan's forum.

I suggest you apply for a signature after buying it, and you can install the software yourself. It's cool.

2.5MM and 3.5MM are just the interface sizes of headphones, both of which are very common in the market.

I suggest you don't need to buy N73. The biggest feature of N73 is its slow response.

You want to buy S60, I recommend you to buy 6 120C, which is cost-effective.