The Doctor wanted the Master to stay on all cost, it seemed like he didn't even think about the consequences.
true. and the key words being 'not even thinking about the consequences'. when i say it's prolly better that he didn't regenerate i'm talking from an outsider's pov. but i'm fairly sure the doctor would argue with me here. aww, tru wuv foreva!

if you ask me, all that rtd really wants to see is john barrowman in pain, emotionally or physically; but preferably both at the same time.

Would be interesting to know if he'd do the same for his new team, at another Torchwood Institute or UNIT.
i'd say he got pretty attached to torchwood three, seeing how he cried like a baby in exit wounds. but still, the circumstances with lisa, after torchwood one burnt to ashes, were different. saving her became his sole purpose in life. i think he gained something since he started at torchwood three, so i think he would still go a long way to save anyone of them, but maybe not out of desperation (unless They took it all away from him and he would have to get them back singlehandedly). sorry, i'm drunkandtired, i'm afraid i'm not making much sense... :/

ok, two things :P
good counting there. ;)