The Republicans can only change the spending and taxing if they are using reconciliation. They can do nothing regarding the rules and regulation which a true replacement bill would require. They can cut subsides, increase subsides, increase taxes and reduce taxes that's all the can do if they are going to pass the bill using reconciliation. Can you think of anything else included in any of those bills? No tort reform, selling across state line nothing along the area, only spending and taxing. 
There was absolute no reason for any Democrat input at this time, because they all do away with the mandate and not a single Democrat was going to vote to do that.