Torchwood - why is it so bad?

James put up his latest review for Torchwood and he's really grappling with why it doesn't work. It's prompted me to have a bash at identifying what's so wrong. My conclusion is this - It's all Russell T's fault. I feel bad for saying this but the blame rests squarely with him. He came up with a great concept but practically everything about the way it has been executed has been flawed and, as he is making the majority of the creative decisions, it's all on him.

POOR CASTING & POOR CHARACTERS: I'm sorry but the actors are a poor fit for the role and the characters are not right almost across the board.

Capt Jack - should be enigmatic but he's more of an attention seeking teenager so why the hell should I care if he has a past or not? He's a show off who spends his time patronising the team. If he was flawed and introvert then maybe I'd give a toss.
John Barrowman - A good looking showman who permanently seems on the brink of breaking into song. Far too attractive.

Eve Myles - a member of secret organisation should physically look like they can handle themselves. She doesn't.
Gwen Cooper - Why on Earth they gave her a boyfriend I don't know. Not convincing in the least. Supposedly the moral compass for the team but too busy organising her wedding and trying (and failing) not to be unfaithful.

Owen - a bit of a twat and therefore reasonably believeable as a technical guy.
Ianto - Gets some funny lines but paper thin.
Toshiko - Why is she even in it?

THEIR WORLD
The backstory to support the concept is sloppy to say the least.

• It's based in Cardiff. A convenient way to keep the costs low for BBC Wales. Should've been London (and before you ask I live in Wales). Russell T was serving his country instead of the story when he took this decision.
• The structure of Torchwood. "Beyond the Government, Above the United Nations" but apparently well known to everyone they encounter in Cardiff. Due in no small part to the drug dealers Ranger Rover that they nicked and pimped up complete with "Torchwood" emblazoned on the side. WTF?
• Where are the rest of them? I thought they were part of a larger organisation with bases in London and other towns? How come, whenever they bring Earth to the brink of Apocalypse, their colleagues never deem it necessary to show up and lend a hand?