Aft Control Lines

I'm planning my next project - leading the halyards, boom vang and reefing lines aft to the cockpit on my 1977 E-32.

Is there any reason why I cannot, or should not, remove the winches from the mast and place them on the cabin top to be used for the aft-led lines?

If I do remove them, will it weaken the mast? Should I replace them with screws or something?

Thanks,

Charles Taylor