1) You are 100% correct the she is a full-on, full-bore heel striker. Yes, this will drive the Born to Run religious cult and vibram whackos NUTS.
2) However, it is has been LOOOOONG known that heel strikers can run fast. They've been doing it forever. There are plenty of 2:05/2:06 africans that heel strike
Meb and Abdi, two more "natural" african born runners, have run low 27's as 100% heel strikers. Think about that. That's way faster than what Baxter just ran. And even world class milers have been known to heel strike.
3) I agree her arm action look odd, however, such quirks don't seem to matter much (except to Alberto)
4) Yes, she has a VERY Long powerful stride. It looks like isn't moving very fast because of her low turnover rate in fact. I often find, whether it be Daniel 7:20 Komen, or David Rudisha, or some others, that a long powerful stride is the key to their "superhuman" performances. Sure, there are also runners with very quick cadences (like Webb), but even he is covering a lot of ground with each stride. At some point, quicker cadence will give you diminishing returns. At some point, one needs to have a fairly long stride length to run fast (there is no magic number, but no matter how quick your turnover, you ain't getting anywhere very fast for very long with an itty bitty stride). Lastly, if you look at very fast, world class runners, a key characteristic, more than the heel coming up to the butt as some seem to focus on, is the trailing leg stretched far behind them upon take-off, i.e., they drive hard through the ground and don't pull that foot up too soon. That is what you see with someone covering a lot of ground.
Here's one of bekele:
http://www.runningtimes.com/rt/images/201210/OM_BekeleOsaka.jpg
