Eh, when you deal with the PHY layer (its a cell network) packets get a bit more confusing. They typically have to interleave pilot symbols (split up packets) into the data in order to demodulate with a better error rate and they tend to keep packets short in order to fast resource allocation amongst multiple users. Short packets help to keep the latency down. How TCP does things ignores how all the lower MAC/PHY (optical networks, cellular, microwave, etc) layers shuffle bits around. tl;dr wireless comm is complicated.

Developing for Qt is pretty straight forward. . . . in two or three days of playing around with Qt creator I was able to setup simple UI's that are not very symbianish (bizillion sub menus) at all for symbian^3. There are a bucket load of examples on Qts website/forums and the community is pretty helpful. As IDEs goes, its pretty good. Anyways, most of the developers for android and iPhone are trash (I expect the same for Qt at some point). They are just mediocre programmers (most phone apps are trivial) getting on the next big wave. This sort of business and market do not attract high quality engineers as its not really interesting.

The best way to describe them to refer to the Qualcomm standard as CDMA2000, and the 3G GSM standard as UMTS or WCDMA.

Buy an unlocked GSM phone. The N900 meets most of your qualifications above but it only works with T-mobile 3G =(. You can get ATT 2G no problem but thats a deal breaker for most people.

Older? Hasn't Nokia been around since the late 1800s? Though I think they were making paper then......

S60 has had flash support for a while now......though the palm will be one of the first phones to support flash 10.1. S60 support will follow a month or so later.

The system works by using E&M waves near the frequency of sound, not sound waves. So an audio version of the signal will not do anything. Sound and Radio waves are different.