It seems to me that when Jesus walked the earth and after He ascended into Heaven men were taught to believe upon Jesus. It was enough to believe. That was the true sign that one was a Christian. There was a direct correlation between belief and faith in Christ
Believing the gospel, trusting and having faith in Jesus are true signs of being regenerated, correct? I think that is the main point the author is making. That we need not wait around hoping God will regenerate us. The fact that we believe and have faith is evidence that we are regenerate.
1. Yes, true repentance and faith are one of the signs that one is regenerate, along with a life that is indicative of one who has truly repented and believed.
2. Since the beginning of time there are those who
professed to believe but who lacked true saving faith. The majority that
profess to be saved did not have true faith. There is an abundance of biblical evidence to substantiate this.
3. The main point the author was making was to repudiate the historic Reformed position that regeneration must
precede faith. As I showed from his very first paragraph, he conflated regeneration, conversion and sanctification. I do agree that there will not be any noticeable length of time that transpires between the Holy Spirit's work of regeneration and the exercising of repentance and faith.
It seems after free-will controversies, it was no longer acceptable to simply believe. You could no longer simply be a professor who has faith.
I would say it was quite the contrary. Easy Believism became increasingly popular among the free-willers and is basically the practice that predominates today, especially in the US. Although he didn't originate easy Believism, Charles Finney firmly established the practice in the mid 1800's. True faith (Fiducia) was abandoned for Historical faith (Assensus), the simple assent to certain propositions, e.g., "Believe that Jesus died for you.", etc.