I think, this class is a little bit broken. No class gets an inniate class bonus to accumulation.
It looks like you have taken the wizard class, removed the "reduced magic appraisal costs to 1" and reduced the the inniate zeon per level to 50.
Now, I think with "natural spells", you mean the natural magic theorem of the arcana exxet (I don't own the book at the moment, but I have read the example for Onmyodo), and I think, if you decide to follow a theorem you can only use this theorem. Therefore the "+10 accumulation to natural spells" would be for nearly all spells of the wyld mage.
Now, we compare the inniate boni of the to classes (wizard and wyld mage)
The wizard gets +10 to magic appraisal (which costs him 10 DP) and +5 to Occult (10 DP). Therefore 20 DP of secondaries.
Then he gets 100 zeon (20 DP). So, he gets 40 DP per level (20 DP primary supernatural, 20 DP secondaries) (so he have "40 DP inniate" + up to 60 DP per level). And he have the reduced costs for magic appraisal.
The wyld mage gets +10 occult (20 DP) and +5 magic appraisal (10 DP), therefore, he gets 30 DP of secoandaries.
Now, he also gets 50 zeon (10 DP), +10 MA to natural spells (as stated above, this should be nearly every spells, therefore I count the whole 50 DP) and +5 MA to inniate spells (at this moment I count nothing). So, it would be 60 DP in supernatural. This would like, 120 DP each level (60 DP inniate and 60% of the DP per level).
This would be a sum of 90 DP per Level. This would be a difference of 50 DP, more than twice as the wizard gets. Okay, the wizard hs the reduced costs, but this should be worth 50 DP.