I agree with cshea - splitting up Hamilton and Chara, as well as pairing Hamilton with Seidenberg, would help - however, I'd go for the following:
Chara - Miller
Seidenberg - Hamilton
Krug - McQuaid
When Bartkoswki plays:
Chara - Krug
Seidenberg - Hamilton
Bartkowski - McQuaid
My reasoning is pretty simple - Miller is a slightly better skater than McQuaid to my eye, in that McQuaid is more upright and prone to getting beaten by a chip up the boards past him (much as Chara is). Miller paired with Chara at times last year, and has the advantage of better gap control. When someone tries to chip past him, he's usually closed the gap enough to make contact and cancel out the attacker without taking an interference penalty, leaving his center and d-partner to chase the puck. [SIZE=14.4444446563721px]Plus having a pairing with two guys who can do 30+ pull-ups consecutively would have to be some sort of record.[/SIZE]
IMO Miller will establish himself as a regular if that change is made - but if he is still rotated out at times, I'd like to see Chara with Krug and leave Bartkowski/McQuaid as an extremely sheltered 3rd pair.
Regarding the trade, I think it's obvious they miss Boychuk to some degree - but also that their issues run deeper on the blue line than having Boychuk could have helped. They still aren't breaking the puck out effectively, and Boychuk was arguably chief offender among those who'd bank the puck off the end boards behind the B's net instead of making a first pass out of the zone.
They're going to have to add someone on the blue line by deadline day - and I have a feeling Andrej Sekera would be a great fit among the UFA-to-be crop.