Decent guide, though I wish you would go more in detail on what the skill does for each or every level where there is a change of what it does (EX:: going from 3 missles to 4 or changes in AoE or range, if there are any.)
About the thing with Ocean of Fire vs. Fury of Land, Fury is better for pvp. Ocean may have a shorter cooldown, but slow>stiffen. Slow is much more dangerous and effective than stiffen in pvp. Ocean is for stages, Fury is for pvp.