[@Rune_Alchemist]
I've might of worded it wrong but if your being confused on the part which says 'As long as you have the knowledge to specify what is needed to be cast' means what he already knows. Meaning that for the moment, he can only empower his Arcane magic with the Ritual Magic currently but as he learns more magic, he can amplify them yes. It essentially is increasing the energy gathered to generate more force behind it so yes, [i][b]he won't start with any elemental spells until he learns them.[/b][/i] ERode's idea is also a good if this starts getting too troublesome lol. 

As for drawbacks, once we start branching out into elemental magic if we focus Ritual Magic on power there is the problem of brute strength over finesse which might imply friendly-fire, arcane magic I see so far as no way to unintentionally harm allies with it unless they run into it literally. Using the ritual circles for control does exactly just that and has generally no drawbacks just burns some time... Using both power and control consumes the most time out of the two depending on what's cast as your creating extra luggage to be carried at the same time. Larger spells more than 5 ft depending on the element when I unlock it when using ritual magic will take several minutes and increase in size as well. 

(Im also fine with just limiting Ritual Magic with Arcane Magic and leaving Elemental Magic untouched until a later date. I think I can do much even with only Arcane Magic or just straight out specialize in Arcane Magic so we can teleport latter instead of walking, thank god.) 
(God I take forever to rant, delete, rant, delete and then finally post ;/)