So after 6 or so hours, Jagex log you out and if you try log in it says "client token failure". Any ways to keep botting longer than 6 hours without having to stop the bot and start it again?
No, it won't. You will still get the client-token failure. You have to refresh RuneScape atleast once per 6 hours. Sometimes it's a bit longer if you are using breaks.
It's not always 6 hours, but in general Runescape will log you out after long periods of time and have you refresh your client. Also if you connection is interrupted between your client and their server.
Running scripts past 6 hours you can simply use SMART Manager which I posted a link to above, if you even took the time to read my post...