It depends if it's a technical limit or functional limit. If the goal is for some user to be able to upload up to 100Mb, but you define it with powers of 10 they'll see a mismatch on their side, thinking the file is small enough.

Not sure it really can. Snore also derives from fnore and I assume it's a spoken language thing.
People don't care how things are written. That's how we get silent letters etc.