I'm sorry but if he takes that advice he'll loose knwledge rather than gain it.
Maguras require more maintenance than disk, the pads wear far quicker so the brake needs to be adjusted to take this into account, the pads are far more difficult to align so it takes alot more time. They are ok on smooth rims but if it gets wet your probably going to be wanting a disk.
Dual disk is great on mod there is nothing that says you shouldn't and it is deffinatley not a bad idea in anyway. You talk about sharp breaking, disk brakes are great for one thing, they have more modulation than maggies, this means they aren't as sharp to start with.
Hydro disks are no better than mechanicals if set up correctly infact i much prefer mechanicals they feel much more solid and more feel to the braking as your physically conected to the brake.
Vee's are amazing brakes, if you set them up well they will out perform most other brake setups. You do not need to change a frame to run magura's you buy an EVO 2 adaptor.
It seems like you were just talking for validation votes there and giving some not brilliant info.
This above is only a vague insight but it is how each works.