I still use my 2* Iruka after having finally gotten him maybe 2 months back, despite the changes I still find him a solid pick especially in Instances or Fox. If you're going to stay completely F2P then in my opinion, you're forced to be more patient than others, that means waiting for discounted events and piecing characters together rather than buying them straight out while also prioritizing power. As much as I would have liked to have gotten Sailor Sakura during the current event I decided to get Medium Refines instead. Having all the characters in the world won't do you much good if you're simply being overpowered.