"If it does fall vertically, the CD will be pretty good and the ensemble will acheive a spectactular velocity before impact with the ocean after 35 seconds of free-fall (Buddha better have a good grip on his cigarette). In the limit of negligible friction, the impact velocity will be ~345 m/sec (773 mph) i.e. around Mach1. The dynamic pressure at this velocity is around 0.7bar, and since the disk can withstand a bursting pressure of ~5bar it will remain intact until impact."

Hmm. I didn't know how to determine dynamic pressure. Dynamic pressure would largely determine it's speed. I used "other" rough approximations: A sphere of ice 20' in diameter weighs about 1/4 million lbs- and "thought" this would fall around 300 mph. And "figured" winds speeds of 300-400 mph would create about 1/2 bar. And then there should some drag from it's lenght and there would also be a vacuum created where the Buddha sat.
I thought it was an interesting puzzle- orginally, I was going to use a larger iron sphere (2 meters instead of 1), but after some "fine tuning" fiqured it would fall much quickier than the capped pipe, so I thought I could make it smaller.
When I first begin with designing these pipelaunchers- they were heavy and high pressure beasts, the lastest ones are lower pressure and compared to total weight are big diameters- they are such low pressure things that instead flying in water, they gettting close to flying in air.
Maybe, a smushed buddha doesn't seem close, but if you switched from steel to aluminum, it's terminal velocity would be lower. And of course aluminum isn't the strongest to weight substance out there.

Another thing I was wondering about today, was using idea of partially floating bridge supports or completely floating the supports.

Anyways, thanks for playing. I don't know how close you are to being correct, but I did enjoy reading about the buddha going on to his next life:)