I liked the Eberle for Strome deal when it was initially made and I am very happy that it has worked out so far. If Beau-Barzal-Eberle can keep producing behind the first line, the Isles are in great shape for offense and it makes them that much harder to play against the next couple years. Plus that line is cheap for the immediate future, even with Eberle making $6 million, since Beau and Barzal are on ELCs.
As for how it will impact other moves and signings, first they have to get JT and Bailey extended. With expiring deals in Kulemin, Chimera, CdH, Hickey, Seids and Halak, that shouldn't be a problem for next season's cap.
From there, I think the Isles can live with both of Ladd and Clutter's contracts for another year. But I don't think you pay Nelson as an RFA. Try to trade or package him for a legit vet3C, ideally on a two-year deal or so. It buys time while some true center's are drafted and hopefully developed.
Then you can put Ladd and Ho-Sang with the new center on the third line and let Cizikas and Clutter play with some mix of MDC, Johnston, Fritz, etc. Whoever earns the job.
You then look to extend Eberle, assuming he continues to play well, and Lee during the 2018-19 season because by then you will know what you have in some of the younger/cheaper players, including Bellows, who I have high hopes for. It also allows for another year to be burned off of Ladd and Clutter's deals.
If Eberle regresses or JHS steps up, you probably trade Eberle or let him walk. But if everything is clicking, maybe you find a taker for the Ladd and/or Clutter contracts by retaining some money, including a draft pick(s) for a cap floor team or a buyout (especially if another strike happens and teams are given some sort of amnesty yet again).
There are definitely some moves that can be made. But one of them, at least to me, is not paying Nelson. I really don't see how he fits long term with inexpensive players like Bellows, MDC, etc. in the system and Ladd making big money already.