Wouldn't the two RHD need to play the same side though? In that case, dressing the 7D might make more sense, but then that means a couple wouldn't be getting that many minutes.
From what I recall, Kaski is open to playing in GR and can't become a UFA until he turns 27 unless the Wings opt not to qualify him.
I also don't think GR would be happy getting Ericsson and Daley, since that would mean they'd have to scratch 2 of their 8 total vets (Elson, Ford, McIlrath, Lashoff, Puempel, Terry and hypothetically Ericsson and Daley) every game.
Also, in an odd way, I don't see Abdelkader being totally scared of a demotion to GR. He'd still be making his NHL salary (and keeping more of it since IIRC guys assigned to the AHL don't pay into Escrow) which is certainly better than taking 2/3's of it on a buyout and trying to find work with another team for probably less than $1M a season, he'd also still be in his home state, and would be playing for a team where he's not constantly getting roasted by the fanbase.