Racist? I didn't think so at all. Because the villain's a Chinese? That doesn't preclude racism, that simply implies that everyone can be fooled, and the Chinese antagonist is actually played with a sympathetic light.
As for Genesis, it provided with the most tangible and important dilemma in the Doctor's life. As far as retcons go, its one of the best ones ones, and thats because it did introduce an iconic new villain, and it present the environment in which the Daleks were given birth into. Its a fascinating social study of the Kelads and the Thals, and a great character study for the Doctor and Davros, and honestly, one of the best serials of Old Who, ever.
In sharp contrast, The Leisure Hive is sheer crap. Its an overproduced piece of fluff, with very little story and that barely makes any sense. If it weren't for Tom Baker's charm and wit, it would've been even worse.