[@Jangel13], Ok.  So transfer is possible with proper comprehension but conversion is not possible due to the fact that the energy would have to be reformatted.  So, if possible at all it would require a complex mechanism to work the conversion and that would be far beyond what Skrik will be able to construct for quite a while.  Understood.

You are in charge so I will accept your decision regarding life transfer.  Your world, your rules.  However, my own understanding of real world energy transfer between living things contradicts your explanation.  In my experience the energy of one living thing is only different from that of another species by a modest amount and the transfer of energy from one to another is both dangerous and relatively easy.  But, enough of that.  I've expressed my perspective.

As an alternate starting path for magic, since his initial driving force to learn it is a combination of curiosity and a desire to repay the trees for the sap, would gaining the ability to see and analyze magic and life force be a more suitable step?  And, if I'm understanding your thinking correctly, while storing fire in an object should be relatively easy it would be far more difficult to store life energy in an inanimate storage medium due to the differing format of the medium.  So, Fire could be stored in Glass, Crystal, or other simple structures while the life force of a plant could be stored in a Wooden Staff or other Wooden Item.

Is my understanding correct?