From a Baptist perspective, of course what separates them from Baptists is unbiblical and erroneous.
But with regard to your last sentence, the only one of those that is valid with regard to the PCA, OPC, EPC and some smaller denominations is choosing a pastor. You're much more likely to see uniformity among Southern Baptists with regard to Sunday School material than you will with conservative Presbyterians. (That's why some Baptists opposed the Sunday School Board (now Lifeway) to begin with.) Some if not all of those Presbyterian denominations don't produce any S.S. material at all. If some is produced, there is generally no expectation that it will be used in any particular congregation. In this sense as well as raising missionary support, some are actually LESS connectional than the SBC in practice when it comes to some things. (Based on what you've written here, I'm sure you object to the SBC as well, but I'm just using it for comparison purposes.) They generally "waste" a lot less money than the SBC, in part because they aren't supporting colleges, children's homes, seminaries and so on. (Most of the conservative Presbyterian seminaries are actually independent. RTS and WTS are the most prominent examples.) I doubt they "waste" more money on Presbytery and General Assembly (none of them have Synods, unlike the PCUSA) than Southern Baptists do on Associations, state conventions and the SBC annual meeting. So many of those objections would also apply to the SBC as much or more than they would to the PCA.
It seems that you're confusing them with the PCUSA in this regard where the denomination owns the building. That's not the case with the denominations like the above named ones that have broken away from it. They can pretty much leave whenever they want and there is little from a practical standpoint that the presbytery or denomination can do about it other than plead with them to remain.
That is why all SBC churches are local autonomous churches. We do not need approval of the SBC to send out missionaries. Our church supports two on our own. The PCA may have changed since I left 36 years ago in details you cite. The fact remains, they have a hierarchy, which patterns the RCC, not the Bible. There are three basic models of church organization . RCC, universal, visible,,,,,Protestant universal, invisible........Baptist local, visible.........The PCUSA is pathetic and apostate. Sanctioning same sex marriage puts them out of the realm of the definition of a NT Christian church. Presbyterian elder rule is suppose to be elected based on spiritual maturity, but in most cases they are elected on social standing. I do know one thing also, growing up in the South in the 50s and 60s. The social structure of segregation was evil and an affront to the Second Great Commandment and God. These pastors in their white churches should have been at the forefront as a representative of Christ of speaking out. Not only did pastors in the Presbyterian Church ignore it, they participated in it. How could anyone who had been called to the ministry and been to seminary, a leader of the people of Christ, get up Sunday after Sunday and ignore it. Wonder how many are in Heaven today. Presbyterians worship services are like a library. No opportunity to express what God is doing in a persons heart. Here is how a typical service ends............End of Sermon.............Small verse..........choral refrain.............march out like robots.............Will you please explain to me how one is baptized before they have any idea what the Gospel means? It would be more meaningful to baptize my pet cat. The parent child covenant is a myth. Everyone is responsible for their own sins. How can one repeat the Apostles Creed every Sunday when it is so full of flawed wording. For example, " I believe in the Holy Catholic church." Hogwash,,,,, One believing that means Universal Church, there is no function for the Universal Church on this earth. The Universal Church never took up an offering, preached a sermon, helped the sick and poor, sang a hymn, administered the Lords Supper and Baptism, sent out a missionary, told the Gospel to the lost, etc. The local church carries out the work of the Lord. Sprinkling infants is unbiblical from the RCC, which makes it a pagan ritual.