As of right now, these players do not broadcast their playing information so there is no way to support them. Broadcasting out intents for playing songs is about an hours worth of development (it is very easy) so I would recommend putting in requests to the developers of these players asking to add support.
Pandora MOG Jet Audio (scrobbling feature is broken in the app so support is not possible)
not sure if its possible.. i dont see it broadcasting any information about what its playing.. i'll look into it but you should request them to add last.fm scrobbling support (through simple last.fm or one of the other scrobblers)
Plus is there any way to turn off its lockscreen player?
Unless its supports last.fm scrobbling through the official player, simple last.fm or scrobble droid then i doubt support is possible. The app needs to broadcast its playing information. I didnt see anything about scrobbling listed in the google play description