CF, DH, and 1B are about it among the hitters.....you aren't replacing Lewis at 3B or either Polanco/Julien at 2B. CC isn't being replaced. Wallner, if they play him 120 games in LF is a top 5-10 LFer. Kepler, like it or not is staying. Jeffers, if allowed to catch 100 games like the best catchers, is top 5-10.
CF? Buxton, Castro, Gordon, Martin, other? And if you say other, good luck finding one (you aren't in FA) that is likely to be great.
DH? Buxton, Julien, Larnach, Miranda, other?
1B? AK can't be relied on any more than Buxton can, imo. But giving up long term assets for a 1 year rental makes no sense, this team isn't THAT good. Severino, Miranda, Julien, Polanco, Buxton (ha, but still), other?
In pitching, I'd target one of the top 4 FA starters w/o doubt. Gotta get one of them. RP is so random, outside a few guys, that I have no idea what to do there.
The biggest improvement from last year is Wallner over Gallo for the year, Jeffers playing 90-100 games at catcher. Julien up all year. Lewis being healthy (fingers crossed), and someone reliably good at 1B. Those three things alone are worth 4-10 wins....
So, the big issue is, how do you, as you and @Riverbriansay, raise the ceiling more? I think it's going to require luck (on the hitting side someone stepping up, like Miranda or Martin).