I have been working on designing a development board based on the Picaxe 08M2
But you decide to ask in the ARDUINO forum for help?
Well, I mean, this is "other" hardware development, isn't it?
IMO, your power traces should be thicker and the traces "further apart" (especially near P2)You are missing bypass caps for each chip that are "recommended" (one or more per chip.) You can probably get away with this on the PICAXE itself, since it's a very small board that has the voltage regulator caps "nearby", but I think that FT232 chip NEEDS a cap on the 3V3OUT pin.You don't have the usual ferrite bead and 10nf cap recommended for USB bypass (it'll probably work fine anyway), and the 100uF cap on Vcc probably violates USB spec when the jumper is set for power from the USB connector.