Is Gene telling Finny the truth when he said what Gene did to him wasn't "anything personal," that is was just "some ignorance inside" him, "something blind"?

I don't think Gene really knew what the truth was so no he wasn't. Gene was full of teenage angst, self identity problems and low self-esteem. His reasons for Finny's fall had to do with rivalry but one can't discount the myriad of other issues that Gene had going on including repressed sexual fascination he had with Finny.