And an hour after that Ianto is dressed and making coffee while Jack yells for him. Why?

I doubt the Hub is the warmest place to be hanging around naked if you're not currently sweating due to some physical activity. ;)

First, Gwen is Torchwood's terrier, she's going to keep at that trail until she finds something, it's best to go on and give it to her.

Also, it's probably better for her mentally if she finishes this quest sooner rather than later. It might distract her from more urgent issues at hand.