2 - If you're asking why sports aren't that big of a deal in Futurama, I imagine it's because the target audience would get tired of sports being brought up all the time. We're more interested in things like time travel and sciencey stuff.
"Real Steel" comes to mind regarding fusion of Sci Fi and sports:)
Apart from that, I guess most sports in Futurama serve as a throwaway gag,
parodoying specific sports tropes on a "one time base". E.g. we experienced Blernsball taking the Baseball cliche of having too many strange rules to an extreme. But -after seeing that joke once- there is no need to retell it again.
That said, the lower budget will also affect (especially TEAM) sport scenes. I would e.g. really love to see a Futurama version of "CyberBall" (American Football with Robots, and therefore going for extreme violence and demolition). Yet, those mass scenes are rather costly.