BTW, I don't see penance as the major stumbling block, but apostolic succession. Penance (perhaps oversimplified) is overcoming evil with good. Think restitution. Apostolic succssion on the other hand may be the greatest stumbling block to a reunited Church. How many Protestant churches do you know of who are willing or even open to accepting the authority of Rome? Yet this is what will have to happen in order for the Church to once again be "one" and for all Christians to be able to receive the spiritual food of Christ's body and blood, soul and divinity. My Catholic two cents.
I think it's a pretty minor issue these days ~ but back in the time of the Reformation/Counterreformation/ReligiousWars it was really, really, really major. People got killed over it.
Still, in contrast, the Religious Wars (in France, between the Catholics and Protestants) pale in comparison to the 30 Years War Phase II that followed ~ that was, more or less, between the Evangelicals and the Lutherans over what seems to have been the order of worship at Sunday services.
Now you talk about killing people, they nearly wiped out Germany over that one!
Proving, of course, that Protestants can, if properly motivated, put the Catholics to shame when it comes to religious legalism.
Most of them would have been quite comfortable sitting in the front pew at most Protestant churches on Sunday ~ on the other hand, they all believed in the primacy of the Bishop of Rome.
Definitely a roadblock. I don't even buy into the idea of having a Minister General in my own church. Religious hierarchies have problems best avoided by not having the hierarchy.
My impression is the Holy Spirit has led us to that point of view. So far, He has neglected leading the Pope down that road ~ but I suspect He'll get around to it someday.