I didn't see where the OP was suggesting the project and context should be the same. Sounds to me like OP wants to be able to configure a set of associations between contexts and projects — if I create a task in context A, the project should be set to XYZ, in context B, to PQR, etc. instead of the current single bucket. I don't think that Omni is likely to implement such a feature, but Help→Send Feedback is the way to request it.
In any case, if you are viewing a context, and add an action, it will be placed in that context, and the project will be set to your default list for Single Actions, as set in the Data section of the preferences. This is the project into which Inbox items not having a project set will be swept on a clean-up unless you have set the preferences for cleaning up Inbox items to require a project or a project and a context. If you're only ever assigning items to a single project when viewing contexts, you could simply configure OmniFocus to put the project-less actions you create in your desired project instead of the Miscellaneous one it is using now. Or create the actions when viewing the project, instead of when viewing the context.