Since all members of our gaming group enjoy the Dresden books our GM has decided to give the RPG a try, but I'm having a bit of trouble wrapping my brain around what's allowed with which kind of magic.

For example, I had considered making a "botanimancer", a focused practitioner that deals with plants. The first couple spells that popped to mind were 1) a ritual-type planting of a garden that would eventually result in plants with bigger blooms, tastier vegetables, etc. and 2) a defensive spell that would cause roots to tangle or trip pursuers. It seems that the first would be a ritual-type spell and the latter an evocation; does that sound correct? Would I need to take both channeling and ritual?

Or would botanimancer be too specific? Would "geomancer" be better since, technically, the first theoretical spell would also be involving nutrients in the earth? Or is it just a matter of flavor and how it works in your head?

And at what point do ideas move from "clever application of your focus" to "cheesing it"? I can't come up with an example for this plant-mage idea, but let's use something that happened in White Knight.
Or am I way overthinking this and just need to go with the flow?  It seems this format of game is less rules-lawyery and more, "sure, that sounds good."