Ellsbury will make plenty of bank. The 30/30 with high OBP and great defense last year (silver slugger, golden glove, runner up for MVP) was probably a career year, but yes, he's very good. Leadoff hitter with leadoff skills and some pop.
I don't know whether Goodwin has the same upside. You would have to gauge that if you wanted to make the plunge.
As for where he plays, he'd play center while Werth is in left and Harper right. Don't forget LaRoche is not under contract for next year, and Morse is an FA after next year.
I don't think he is worth the players it'd take for a 1 year rental, so it would have to be a free agency move. The quirky thing is th efit is not bad, especially if Zander Bogaerts can't stick at SS. Espinosa at SS would be a great fit for them, and we have Lombo to keep 2d warm until Rendon is ready. They also have Kalish and Jackie Bradley Jr, so it isn't 100% clear they are going to go all in to keep Ellsbury. Most likely there's no real possibility of a deal, but we may know more about Goodwin after next year and whether he is the answer or we take the plunge for Jacoby.
Blue - chew me out.