The trek from Kasol to Chalal will take 1-1.5 hour. For other treks you can go to Magic valley, Weichin. You can explore places like Manikaran, Tosh, Malana and Rasol.
If you are going to Manikaran, yes you can return the same day. Yes, and Magic valley too can be done in a day but you have to start early morning. But when going to Magic valley people do camp at Weichin and while returning visit Malana.
Read my blog on how to cover parvati valley in budget...All your doubts will be cleared.. You can ask any doubts if you have. You can return from all these you start erly in the morning 1)Malana 2)Tosh 3)Rashol 4)Manikaran