Is it possible to have a basket or something on ziplines and have it so we have to use our energy or something and pull it back and forth instead of having ziplines only one way?

That would be pretty slow travel, unless a "system" is implemented with perhaps counter balances, ropes and pulleys. This would more than likely take a good amount of resources. I'd still build one though.

Three words "Human Scale Slingshot" combine this with a padded landing item maybe we might make it to the gas station and get more that two billy Hogg buggets

Oh lord, no.