I wouldn't say they aren't in the way, 8-9 million in dead space could get you one heck of another player. That said buying out Saros in 4 years doesn't kill you if Askarov turns into the goalie he was drafted to be.
To me, the only dead cap that was a bad contract is Turris (which isn’t a high number).Yeah you can certainly work around having to get rid of bad contracts but that doesn't mean they aren't problematic. At a minimum, because of the Duchene, Johansen, Turris contracts we're going to have to get rid of someone we would otherwise keep this year and as you say we could have added another good player into the mix without the dead cap hit we have.
Duchene was a stylistic choice that Trotz made, he'll have to live with that 6ish million dead cap number for the next 2 years.
Johansen's salary is unfortunately still dead cap for the team even though he'll be LTIRetired. But that's gone after this season so whatever.
Dead cap seems to be a standard operating procedure for the NHL now. You have to hope your team keeps the DC % low to get the most available capspace but there will be some % of "waste" every season.