Was Hoid trying to become an Elantrian kind of in a way how Kelsier was able to connect to Preservation to take up the Shard?
Yes, the thing about it is you're getting Hoid before he knew as much as he did in Scadrial era, so what he was trying to do was completely ineffective and it couldn't have worked.
Doesn't it get weaker the farther away you are, so it wouldn't help at all.
Well we have an example of an Elantrian on Roshar, so.
Yes we have an Elantrian on Roshar, but we don't see him use any powers, and his skin is dark on Roshar rather than glowing, granted that could be a disguise. That is something to be aware of.