Redmine

Hi @all,
Last week I failed to update a Plugin, and the following actions end up in a total mess.
I had to fix everything: ruby, rails, redmine, databases. It was horrible.

Now, everything is up and running again, but I still NEED to upgrade some things - but - what´s primary and whats secondary todo?
My setup with the plugins isnt realy simple (for me).

Here is my actual status:
Environment (before):
Redmine version 2.5.2.stable
Ruby version 1.9.3-p551 (2014-11-13) [x86_64-linux]
Rails version 3.2.19
Environment production
Database adapter Mysql2
SCM (before):
Subversion 1.8.8
Git 1.9.1
Redmine plugins (before):
redmine_bootstrap_kit 0.2.3
redmine_checklists 3.0.1
redmine_code_review 0.6.3
redmine_knowledgebase 3.0.4
redmine_login_audit 0.1.5
redmine_maintenance_mode 1.1.0
redmine_planning 0.7.6
wiking 1.0.0b

a "must-have" is a secure and stable redmine, with plugins redmine_checklists (R3.1.1 with Templates), redmine_knowledgebase (=big depency problems), and full functional git-server-plugin.

Could anybody please tell me what to upgrade first? I fear i would fall in a looping trap of depencies and inconsistences...

regards,
Rene´