Redmine - Best to begin with

As I work through my journey for the project manager experience, I learned about an open-source project management application called Redmine.
I found the application to be really user-friendly and flexible.

I can summarize my working experience with Redmine with below pointers:

Features:
1. Configure the SCM repository in Redmine. Redmine will pull up the updates into the SCM automatically and display it in the browser which is helpful for the review purposes.
2. Capturing Code Review comments after installing the Redmine Code Review plugin. Administrator/manager can define a custom tracker called "Code-Review" for the code-review comments for easier differentiation between bug/feature and code-review comment.
3. After installing the Redmine Commit Relation Editor plugin, we can explicitly associate the code changes with the trackers defined in Redmine
4. Redmine can also automatically associate the SCM commit comments to the Redmine's issue. e.g. If the developer puts a comment in the SCM commit message as "fixing #55", in Redmine's repository tab, it would display the link to the Redmine issue and also display the commit details on the Redmine issue as well.
5. In Redmine, the administrator / manager can explicitly map the SCM user-id to the Redmine user-id, thereby helping the code review to relate the developer and the change.
6. Redmine has the Forum features which can be helpful for maintaining the design discussions or the root cause analysis process which can be handy for future reference when we come across the same issue a few months later or we have questions about the thought-process while coming onto a decision in the past.
7. Redmine also has Calendar feature which can be used for tracking deployments, maintenance windows, Promotional events, Vacations, etc.
8. Redmine's Roadmap feature can be useful for tracking the progress on the releases and its individual requirements.
9. Redmine has a very user-friendly time tracking mechanism as different from the usual home-grown time tracking tools.
10. Redmine can also version control Documents & files.
11. Redmine also has a in-famous News & Wiki feature that can be used for internal team communication.

Missing features / Concern points:
1. One project holding multiple SCM repositories.
2. Built on ROR (Ruby-On-Rails), so maintenance / trouble-shooting can prove to be difficult, if you do not hold resources with these technology in your team.
3. As the dependency on Redmine grows and the application becomes critical for the team, Redmine-administator role would be a necessity.