If you are going to start using e-mixes you should invest in the proper hardware like flex fuel kit/tune and/or ethanol content sensor so the car can calculate proper parameters based on e-content. Makes things much easier. Also when you upgrade turbo, fueling etc all that is already there. Just my opinion bro
I would replace the intake filter since the car has some miles, you can get a filter from the dealer for like 20-30! And then eventually I would get a Dinan intake.