Hi. After some time of just reading I registered to the forum because I have some questions I couldn't find answers to.
First there is the Nightwatcher. She seems to be able to do some very powerful stuff that to me seem even beyond the power of shards. Could a shard hack a magic system at will? Could it just so create creatures who are able to metabolize food directly into stormlight, like Lift does? Seems to me this removes a lot of restrictions to the magic systems we know. Similarly: Could Sazed just give an intellect like Taravangians on his best day to all of the people on Scadrial? Does he even have this amount of genius himself?
To me it seems that the Old Magic could be something totally different, something that has nothing to do with shards. If so, if it is something that predates the shards, perhaps Cultivation cultivated this ancient magic system and so made it something that now is attached to herself? (Though the intent of "Preservation" would fit this behaviour better).
Now what has Hemalurgy to do with it? Has anyone ever asked Brandon, if Hemalurgy could steal a boon granted by the nightwatcher? If the answer is yes, its clear that Old Magic works quite similarly as the other magic systems (and Lift is in quite some danger if knowledge of Hemalurgy gets widely spread), if the answer is no, we'd know it's something special.
My bet: No, it could not be transfered.