The best place to get help is the forum. It is read by many experienced users of DCP-o-matic (including film-makers, projectionists and cinema technicians) and myself.
You might like to read a short discussion of reasonable expectations for DCP-o-matic.
If you find a bug in DCP-o-matic please update to the latest version before reporting it, as there is a good chance that the bug is already fixed.
If you want to discuss something privately please feel free to email me (Carl) directly. The number of emails that I receive is usually unmanageable so please do not be offended if you receive an automatic reply directing you towards the forum. I will try to answer where possible.