I have a reply to comments about resolving conflicts. I believe there’s no difference in number of conflicts, whether you commit to the trunk or merge the branch. If conflicts exist in a branch, thay would also exist when committing to trunk.
The only difference is that when merging branch to trunk (or other direction), you have to resolve all conflicts together. But sometimes that is better – I don’t want to worry about them every time I commit, but I’m prepared to work on them at the end of subproject.

CI and “branch-always” are not incompatible: you have to find a good comprise; maybe you’ll get more satisfaction with the “branch when needed” approach (see http://svn.apache.org/repos/asf/subversion/trunk/doc/user/svn-best-practices.html). Just don’t neglect the benefits of branching.

“do NEVER work directly on the trunk, unless you have to deal with a bug which is quick and easy to fix (a few characters), or if you have to ADD a few files which hold no logic (like media files: images, videos, css, etc)”

But what if you are doing Continuous integration? We would want to keep committing to trunk and merging every commit so that trunk is release ready at any point of time.

Thanks