Inherited a team in 5x5 25 man NL ONLY keeper league

[stealthrunner]

I have been wanting to get in this league for a few years. This is their 10th season, very good teams. I have been told by a couple of other managers they would rank my team as number 5 in offseason.
We do 5x5 roto, with 25 man roster. You can keep up to 12, but no less than 5. Salary cap of $300. NL Only league.
You can keep a player for 3 years. All players on team are in their 2nd year or final at this time.

My team consists of:

C *Ramon Castro NYN 2nd $8
C Todd Greene Col 2nd $1
1B Sean Casey Cin Final $12
3B Morgan Ensberg Hou Final $5
3B #Jeff Baker Col 2nd $10
3B Aramis Ramirez ChN Final $19
2B Ray Durham SF 2nd $14
2B #Bo Hart StL 2nd $6
2B Jose Reyes NYN Final $10
2B #Damian Jackson SD 2nd $4
OF Geoff Jenkins Mil Final $8
OF *Ken Griffey Jr Cin 2nd $20
OF Reggie Sanders StL 2nd $18
OF Adam Dunn Cin 2nd $23
OF Larry Walker StL 2nd $21
OF Choo Freeman Col 2nd $19
P Jason Isringhausen StL Final $17
P Brandon Webb Ari Final $25
P Edwin Jackson LA F Final $7
P *Robb Nen SF 2nd $9
P Jeff Weaver LA 2nd $7
P Wilson Alvarez LA 2nd $1
P Elmer Dessens LA 2nd $3
P *Shane Reynolds Ari 2nd $8
P Steve Sparks SD 2nd $7

I would love input on what you think? Who should I definitely keep, who should I trade for young guys or studs, etc. I know I have people interested in Dunn, Ramirez and Izzi.