The people in your session when you joined could only see you. Once you die is when other people new to the lobby will be able to see you. Any sp car is invisible to the lobby so you are inv otr when driving it.
Not really, he glitched dm into sp and then did spmp by getting arrested and it didn't kick him. Sad to say there were no peyote but still had access to other stuff (which is more important to me than a plant lol)
Full spmp which contains peyote is patched, the most you can do with spmp now is either play as sp character or store sp vehicles to your online garage.