You might have saved from felix console directly & creates a config file. You can configuration has config or a node.  What is the issue with having as file?

You can have boost in aem6 also make sure you install latest oak  Hot fix 6316  [1].  Details how to configure at http://jackrabbit.apache.org/oak/docs/query/lucene.html[1]    http://jackrabbit.apache.org/oak/docs/query/lucene.html

The message "SharedItemStateManager Validating change-set hierarchy"  is due to include of your startup script [1] which is checking the repository inconsistency before saving the changes.The message "PUT /libs/sling/topology/connector.xxxx" is HTTP call from topology to verify Sling is properly sta...

Each Service pack are important update that includes security, performance, stability, and key customer fixes and enhancements. You should always plan to install latest one & if you have timing issue can delay installation but do not ignore to not install it.

Can you verify the spelling at [1].  It should be "References" [1]  /libs/wcm/msm/config.author/com.day.cq.wcm.msm.impl.actions.ReferencesUpdateActionFactory

Out of the box title is excluded, configure the CQ MSM Content Update Action .  Steps are [1].  If still does not work file an official support request. [1]   https://docs.adobe.com/docs/en/cq/5-6-1/administering/multi_site_manager.html#Creating%20a%20Rollout%20Configuration

If there is permission denied you get those message. Make sure you have logged in

http://dev.day.com/content/ddc/en/gems/msm-and-translation--best-practices.htmlhttp://dev.day.com/content/ddc/en/gems/streamlining-multilingual-content-process.html

Can you please elaborate more with screenshot & actual implementation? Are you getting blank page, If so Check the log files if there is any problem.  

Go to image set editing and reorder it.http://docs.adobe.com/docs/en/aem/6-0/author/assets/dynamic-media/image-sets.html