Touki's CU is an absolute hammer, with 70 grade movement in both directions. It is quite possibly one of the best CUs in baseball right now.
The SL is good, but perhaps not needed when the CU is so devastating. Dialing in the CU rather than trying to throw both might benefit him.
The FA is also pretty flat, but his SI is quite good.
I agree that he should focus on SI/CU/Split, and should almost certainly be a guy who can go 9-12 batters...perhaps better since he has a truly elite pitch with that CU.
Oh...and Touki most certainly does not "suck". He is a very talented arm who should be able to be developed by a competent management.