That's the problem with dealing Lucic. Easy to sit back in a chair and say deal Lucic for a haul, sign Hamilton long term, get a top-4 D. Profit???
Being an impending UFA, I don't think he holds much more value than a guy like Eriksson. Who's going to give up a top-15 pick and/or a blue chip prospect for potentially just one year of Lucic? Trade a couple of your best assets for Lucic OR look to the free agent route at guys like Stewart/Stafford/Ward? Not as impactful, but they don't cost assets and likely don't take up as much cap space.
There is no way I want anything to do with Eriksson long term. He'll be 31 at this point next year and you'll probably have to give him at least 5 years.
Three years from now when Lucic is 29. Will he still have trade value? Depending on he length of the contract and total value, I think so. Especially when you account for rising cap. I think if you're trying to manage your assets for long term sustainability, you sign Lucic and look to deal Eriksson/Kelly/Seidenberg. I'll throw Smith in there too because he's making pretty good coin and isn't what I consider core material (although I like the player, even if I'm in the minority).