"Take contraception and abortion for example".
It seems that 2/2 does not follow from 1/2. If, for example, contraception and/or abortion is clearly immoral AND contrary to the common good, the church has an obligation (to society and not only internally) to pursue it as also illegal, not as dominating, imposing it on, society but as a contribution to it. The same would, in this sense, hold for something essential to the common good.
The problem as I see it is (at least) threefold:
1. how the issue is understood, validated, articulated, and pursued. 
2. how the processes and conclusions within the civic/political processes, decisions and administration are respected, 
3. how matters of membership, individual discernment and conscience are respected.
It seems to me that our Church fails on all three counts. Plus, Church maintains its right despite its obvious failing, while reasonable persons see these failures as denying the right and obligation.  And that is the real problem.