is it possible to sell workflows and bots made with uipath to customers, and letting them use it without them having to download uipath?
No, not possible. They have to buy bots from UiPath. Orchestrator is optional. Technically your clients can download community edition & run the workflows developed by you, but it is illegal.Community edition cannot be used for commercial purpose.
And if I send my bot to a friend, is it possible that he can only download uirobot, and saves the workflow in his computer. Then I can run it via orchestrator?
No, I dont think even that is possible.
Technically, you can use it in small companies. Check out the license conditions for the Community Edition:
You just cannot use the Orchestrator platform for anything else other than training.
And I suppose your original question is answered here:
I think small entities can use Studio, but not clear on the UiRobot. So you may have to run the workflows from Studio manually.