Good points all around, especially on ERod.
I think we can hope for more of the same from Ross, which has been pretty darn good, and good seasons from 3 or 4 out of C Smith, Kelly, Barnes, Hembree and Scott. A return to form from Kimbrel would also be a huge boost. I still think there's too much hoping and praying going on with the pen without Zeigler, Uehara and Tazawa. Assuming all starters are healthy (unlikely), we can add Buch or Pom to the pen, but even then, I think we fall short by at least 1 top quality pen arm. I can't see us standing pat with this pen.
The rotation shows much more promise, and you hit on a few reasons why. Last winter we were dreaming of Buch and Kelly having full productive seasons with Price, Porcello & ERod commanding the TOR. The ERod injury hurt, but it did provide a slot for Wright to come in and save the day. Looking at GS'd this year vs projected next year, there's a ton of room for improvement:
Price 35 GS'd to 33 (-2)
Porcello 33 to 33 (No change)
Wright 24 to 28 (+4)
ERod 20 to 28 (+8)
Pomeranz 13 to 25 (+12)
Buchholz 21 to 15 (-6)
Kelly 6 > 0
Owens 5>0
O'Sullivan 4>0
Elias 1> 0