The early church also sold all that they had and held everything in common.
That is not a model for the church today, however. Those were extreme times. One could be arrested and held without trial, or even executed, just for being part of The Way Sect, as the Sanhedrin dubbed Christianity. When the church -- Body of Christ -- comes under such persecution anywhere in the world, and it won't be long, then will be the time to return to that model.
It is important - but there are also men who, void of a seminary education, taught sound doctrine (e.g., the Tozer example). We are also not talking about a three year education (I'd imagine most MDiv's are about 8 yrs including undergraduate - add to that for a DMin or PhD). But you are right about the importance of education. The disciples had Jesus Christ, we have the Holy Spirit – we are not left alone. (And the role of the apostle didn't exactly equate to the role of the pastor - I don't know the education NT "pastors" received, it seems like much came from the apostles).
Yes, I believe there are men such as Tozer who were divinely equipped to preach and divide the word. Such men are, as you know, few and far between. The length of time required to become educationally qualified may vary from man to man, but is still -- in my opinion -- necessary. I believe you are correct in assuming the education necessary for first and second century pastors to assume their duties came directly from the apostles. Obviously we see Timothy selected and groomed by Paul, and he went on to become the pastor at Ephesus, taking to the pulpit in that church even before the apostle John held the post before his exile. Titus was also a protege of Paul's and had become a pastor late in Paul's ministry.
Onesimus, according to many church writers, having been freed by Philemon at Paul's request, went on to become a church leader by the early second century, and Clement did as well, having been associated with Paul. All, I am sure, benefited from their association and education under Paul.
Seminaries and other educational programs have also stepped up to fill the void left by the local church. Many churches “outsource” their teaching. Many members seek alternate means of learning to fill the void in some churches. Much of what is taught in seminary can and should be taught to the church.
My concern isn't seminaries, but the professionalization of the ministry. I could see this (in extreme cases) resulting in para-church “churches” where the professional’s run the show and the members are little more than consumers or patients getting a spiritual “tune up.”
Google "Jerry Johnston, Kansas City" and see how such an arrangement can consume a man and destroy his ministry.