I thought that Kwaan says something about the Ruin being able to change information on paper as well as those stored in the metal minds??? I should go back and make sure though.
Ruin can change information on paper, as well as in metalminds. This is why the steel plate remains the same, while the rubbing (and metalmind rubbing) and the translations are changed.
However, Does hemulurgy(i think is spelled it wrong) grant the person who undergoes it allomantic powers? It does, i mean it must. Marsh confirms that. So hemulurgy, that metal Vin finds in the end of the second book, and TLR, those are the three ways...
Where'd you get the idea that it must grant allomantic abilities? It's just as plausible that the Inquisitors eat Elend's metal and get allomancy from there. We do, however, know that inquisitors do use allomancy.
And it's hemalurgy. So you were close, but not quite.
Kwaan could have hemulurged himself(lol im ravaging the word)in fear of the Ruin altering what he knew...
The word you are looking for here is "hemalurgified." Also, he wouldn't have done that unless he thought it would prevent Ruin from altering what he knew. There are two options here. Either a) hemalurgy was already around, in which case Kwaan would likely know that becoming a hemalurgist wouldn't help him, or b) hemalurgy wasn't already around, and Kwaan wouldn't know enough about it to risk it unless he was desperate and had some idea of what it might do (or thought he did). But it's a good thought.