Twitter has updated the look of their app area, but all the settings are pretty much the same. If there's a setting you are confused about or can't find, please let us know what it is.
As for the Bad Token message.. there's a couple odd things going on. First, when I click the login with Twitter or LinkedIn, the JFBConnect code calls a link on your site like:
https://www.YOURSITE.com/nullindex.php?option=com_jfbconnect&task=authenticate.login&provider=linkedin&return=null&t=1
The t=1, return=null and nullindex.php are all incorrect values. I'm unsure where those are coming from.. but LinkedIn actually still works (strangely) yet Twitter throws the Bad Token error.
I see a lot of 'optimization' stuff running in the code to minimize and re-arrange Javascript. I'd recommend trying to disable that to see if it fixes things. There is a certain order that our Javascript code needs to be placed on the site to ensure it executes properly and it's possible the optimizations are causing issues there.
Beyond that, normally, a Bad Token Error indicates a couple other server problems, primarily that your servers' time is way off. That's something to look into if you still have issues after testing with the optimizations turned off.
I hope that helps,
Alex