DC Team vs The Doctor

How exactly does the sonic screw driver prevent anyone here from ruining the Doctor?

Doctor dies, they congratulate themselves on a job well done, leave, he regenerates into Matt Smith and gets into his Tardis. The rest is lol. 

I'm assuming that he doesn't start in his Tardis and that they don't know in advance about his ability to regenerate. 

How exactly does the sonic screw driver prevent anyone here from ruining the Doctor?

Doctor dies, they congratulate themselves on a job well done, leave, he regenerates into Matt Smith and gets into his Tardis. The rest is lol. 

I'm assuming that he doesn't start in his Tardis and that they don't know in advance about his ability to regenerate. 

 @Primarch said:   

Well once he's inside his Tardis, they have nothing that can get through to him and he can easily make a weapon that would annihilate the Batcave, he could easily make a weapon that would knock them all unconscious, essentially whatever weapon fits within his morals and wins this battle, he can make. 

I must admit the only reason I thought he would die is that I misread batcave as cave  and thinking that he wouldn't be able to start within his Tardis therefore putting him into a fistfight against people that are much better at fighting than him, as you say the Security System is his plaything.

Also, what do people here generally think a sonic screwdriver can do? It seems to canonically vary but I've never understood why he wouldn't be able to just use it on biologicals to (say) knock them unconscious.

He would talk to them to death
And why do Martha and Mickey have to die? Donna was obviously the worst companion