I still am a huge Torchwood fan. But I really, really dislike MD. It was too drawn-out with too much random violence and hanging plot threads. It simply was not executed well. Especially with the problem of Rex. The best shows really have most everything tied up by the end of the season, and if you leave things hanging like that it's actually not that promising. Viewers like a resolution, not more twisted complications. [side note: this is why PotC2 was the worst of its series.]
Really, if Jack is to be further explored, I think bringing him back to DW as a semi-frequent companion would be best. Maybe getting about the same amount of screentime River did the last few seasons.
The thing is, Torchwood
can't be recreated. There is a reason One was never rebuilt, Two closed down, Four was never found. Besides that, they used to get funding and everything directly from the heads of the British government. If they're gallivanting off in America, how are they gonna be funded? If they're not funded, how are they going to have the equipment necessary to take on worldwide attacks and such? And how are they going to get to London fast enough when aliens inevitably strike there?
Honestly, the only way I see Torchwood continuing is if Three's surviving members find Four and join up with them or something.
Insurance for when the Doctor isn't there, sure. But he's got a phone [though he seems to rarely answer] and pops back and forth often enough that he's hear about some huge event. That's why MD makes no sense- would Martha have not called the Doctor? Would the Doctor have not notice something amiss? He's been back a crap-ton of times with Amy and Rory supposedly during the events of MD. [ooh new idea MD happened in the aborted timeline of series 5's finale]
Torchwood's not overstepping their bounds, no, but they're overstepping their abilities. They haven't got the resources- no you know what I've said it already. The Doctor's wishes are all well and good [and are more along the lines of "humans should start developing planetary shields and practicing communications with extraterrestrials"], but they really can not conceivably take this on themselves. They're only humans and semi-immortals. They haven't got a TARDIS or insane knowledge of the universe's intricate workings. They barely saved the world in the last few seasons and even then lost a hell of a lot of people. And the thing is, both times it wasn't even an exciting and brilliant resolution- it was hell. It was terrifying. It was depressing. And it worked once, really well, but you can't keep doing that kind of thing over and over for your conclusions. People don't watch to be sad and horrified- they want at least a decent end to the emotional turmoil.
Honestly MD would have worked best as a movie if anything. It was stretched too thin for ten episodes. Two and a half hours would have been perfect.
Plus if you don't want to see any more Torchwood, then don't watch it. Problem solved. :P
This, I don't ever tolerate anyone saying, especially when you know perfectly well what I mean. I mean I don't want to see another disappointment attached to Torchwood. I don't want it to
exist, because when that kind of thing happens people start forgetting about the brilliance that came before it. It'll be like Brett Favre's career.