Oudeis, these are two excellent observations here. I agree with you on both points. From a logistical standpoint this makes a lot of sense, Brandon's magic systems for the most part work logically and these follow suit with what we know about both Preservation and Ruin. I suspect that a Lerasium spike would retain it's charge as you mentioned. I do not think that it would be that it is limited in what it would give, but rather, it would depend on which bindpoint was used (Spike placement). Also, I completely agree that it probably requires an Atium spike to steal off world magics.