1) At first; as many components as possible (particularly the cryo valves) should be off the shelf. 2) I am guessing that the LOX should either be atomized or at least put into a very fine spray and possibly not injected solely at the top of the motor. 3) I think the plumbing should be rigid due to the extreme temperature differences the system will see. 4) A well built spin caster would give us quick repeatability with the fuel grains and could possibly be built in such a way as to be portable. i.e. mounted to a trailer for trips to the desert or promo opportunities. 5) I am curious if the strange post-burn parrafin geometry is due to too much transient heat during the burn. If so; could we run cryo plumbing around the motor casing and keep the parrafin cold and solid everywhere but the burn surface? If so; would this change the burn characteristics of the parrafin? (i.e. ignition temp, burn rate, etc.) 6) Probably a question for Andrew, but can we set the rocket up so that if the initial nav system detects a noticable change in direction (+ or - som many degrees from the vertical) the LOX feed shuts off and the chutes are deployed? I think that a system of this size and complexity might have some balance issues. 7) Intellectual property rights NEED to be discussed. I know that some of us would love to see this develop into some sort of business venture in the future.