What are the shank diameters of MegaBore Drill Bits?

Does the MegaBore drill bit require a specially designed shaft for MegaBore bits?

I have a 1/4" diameter extension (4.5 feet), and I want to know if this bit will fit without any other special MegaBore extensions.

http://www.lsdinc.com/content/product_details/22

I got an email response from LSD. It looks like I will need to get a 7/16" Connecting-Hole MegaBore Shaft, which is 1/4" in diameter, and then connect the MegaBore Shaft to the regular 1/4" flex extension.

Email Response:
"Hello,

The 7/16” Hex, is the standard size for similar bits.

Thanks

Customer Service Department

Labor Saving Devices,Inc."

I have a 3/8 " drill. What size drill bits would work in that drill? Can I use a drill bit that is less than 3/8. Can I use a drill bit les than 3/8 up to 3/8. Would it work if I use a bigger drill bit like 1/2 inch?
What does it mean a drill si 3/8 is that measuring the circumfernce or diameter. Does 3/8 mean the maximum drill bit is 3/8

My late father owned a machine shop. He had several boxes of huge drill bits - some are over a foot long and maybe two inches in diameter. But they haven't been used in years and are now a bit rusty. Do they have any value beyond scrap steel? Is it too much trouble for someone to clean and sharpen them, etc. ?

I cannot find one anywhere, and need to drill a hole in wood that is 4" in diameter. The biggest drill bits I can find are 1" in diameter.

I have a cordless drill and the chuck is only 10mm but ive seen drill bits up to 30mm diameter how are you suppose to get this to fit. Thanks in advance

preferably 14-15 mm in cutting diameter..i seriously can't find them anywhere. specifically looking for 14.5 mm glass cut diameter (about .5709 inches)

I making a cordless drill and I need to figure out what battery to use that will power a High Torque Mini 12V 600 rpm DC Gear Motor, and fit within in these dimensions 25mm diameter and 90mm in length. I also need the battery to be rechargeable and be fit to use for a battery amateur like me so no batteries that will explode in my face if I over charge them. Cheers!

It needs to be able to hold #68 drill bits, which are 0.031 inches in diameter.
I need to use really small drill bits with my dremel and it looks like I need some kind of attachment for the dremel to hold the bits. Do Lowes or Home Depot sell some sort of attachment?