The reason I'd consider trading Kimbrel now is because it accelerates the "quick fix" Hart & Company were looking for. IF it is to Toronto and you get back Norris plus, you've "fixed" the pitching for the foreseeable future as well as improved the overall system depth with the deals (Norris, Miller, Fried, Jenkins, Peterson, Peterson, Smith, plus Pentecost and another piece in a Kimbrel deal, and 2 of the top 30 picks in this year's draft) while clearing the same amount of money that lies dead in Uggla and B. J..
Now you want to be competitive in 2015 - 2017, right? Keep Gattis, sign Mike Adams for half what Kimbrel makes ($4 million), trade Minor for Charlie Blackmon, and sign Shields ($18 million) and payroll sits at less than $103 million INCLUDING Uggla and B. J.. If you had to go a little higher to get Shields, there would be plenty of room.
CF- Blackmon, RF- Markakis, 1B- Freeman, LF- Gattis, 2B- Callaspo, 3B- Johnson, SS- Simba, C- Bethancourt
would have a really good chance to be "competitive" with a rotation of Shields, Teheran, Wood, Miller, and Norris.
Maybe you're a little less confident without Kimbrel at the back end, but I'd be pretty comfortable letting Grilli, Adams, and Johnson handle the 9th until Simmons (or even Vizcaino) can take over. Moving forward, you'd have Uggla and B. J.'s money coming off to pay the raises, meaning ANY payroll increases could be entirely devoted to signing a free-agent bat or possibly thrown at Moncada.