What... benefits....?

how much funding has down-ballot candidates ever gotten from the green party? Go ahead. Publish the numbers.

how much campaigning does Jill or other national green leaders do for the state office candidates? (none?)

Green party candidates are basically independents who align with a certain je ne sais quoi. they build their own campaign, source their own funds, and generally have extremely limited party support. If there's party help at all, it's strictly at the local level, with multiple people helping each other out.

The national Green Party does extremely little to help down ballot.

I don't know about the other parties, but to my knowledge the only third party that has "significant" support down ballot are the libertarians, and even that is... dubious. yes. Elections are way more expensive than they should be.

But again, you're missing my point: Bernie Sanders, as an independent, has done entire orders of magnitude more good runing for senator than Jill Stein has ever accomplished. He should be the model for how to get 3rd party influence at the federal level, not someone who has yet to win any election anywhere.