In terms of the Pasta turnover thing...he's actually turning it over a lot less in the playoffs than in the regular season. 4.05 giveaways/60 in the regular season; 3.06 in the 4 playoff games so far.
Also I think it's a little overblown. The guys who are on the ice a lot and also have the puck a lot are the ones who turn it over the most. The top 10 of regular season turnover rate is a who's who of best players in the league. Malkin, Pasta, Panarin, Barzal, Draisaitl, Kucherov, Marchand, Marner, Jack Hughes, etc. Additionally, the Bruins are coached at times to try to make low percentage passes instead of the "safe" play because they would rather try to get it to a shooter in a spot where a shot would have a 15% chance of going in rather than safely moving the puck down the boards or taking a shot that has a less than 5% chance of going in. Essemtially they'd rather try to pass it to a high danger area, even if the odds of completing the pass are low, than take a no danger shot. Thus, more turnovers.
I do think that in Bergy and Krejci's absense Pasta has tried to fill more of a playmaking role which has made him look a bit off his game.