Two small questions: are the keycaps "thick" PBT? And how do the different layers work? Can I switch and stay in a particular layer?
No the dsa caps from sp that are $37 are not thick pbt, they are regular DSA profile regular thickness pbt.
There are 2 type of layer switching..
You can either Toggle layer, which means, hold down toggle layer button, and press the corresponding key to trigger.
OR, you can Push Layer, which means you press the layer button, it holds that layer until you POP layer which returns you to Normal, Or alternatively, You can setup links from any layer to any layer within any layer.
The layers are very powerful, and you can pretty much do whatever you like.
And if you know C, well, then, there's actually no limitations to what you can do, just limitations on how much time you have.
OMG, the teensy also supports overclocking.. i just found out.