The dev community doesn't generally encourage having one-on-one conversations for issues. Generally all issues are discussed in the this mailing list publicly. Unless it's a special discussion on a certain way a feature must be designed/implemented/etc. the community may opt for a web conference; but that also could happen mostly in the architecture list; not in the dev list. Please send your questions to this list itself. Generally you would receive much swifter responses because there is a group of people watching this list.
However if you feel that you are not receiving fast enough responses, because the questions are too specific to your use case, or not something that is supported out of the box from the product and something that is not documented as available in the product, then I would encourage you to contact WSO2 support  in order to get all your questions answered with guaranteed SLAs.