If faith/belief came before baptism then I'd probably start questioning the legitimacy of my own baptism and I assume many other Christians would too. So if I didn't have enough faith at the time i was baptized, would I need to be baptized again?
Well, the examples we have in the New Testament include the Ethiopian, who was told that if he believed with all his heart he could be baptized. So it certainly should be a definite belief. So it's not the amount of faith, but how definite the faith is that we have in Jesus Christ.
Also, If this were also the case, shouldn't Pastors make this a requirement for those waiting to be baptized?
Yes, although in my experience, it is not the pastor alone who would check this. As far as possible, churches should ensure that candidates for baptism do indeed believe on the Lord Jesus Christ.
As far as the jailer at Philippi and his family, what I got from that was baptism was still a requirement even after you believe.
In Acts 19:1-6 it sure does seem to say that repentance and baptism comes first then you go on on to believing in Jesus and be baptized by the fire and Holy Spirit.
No, those verses are talking about people who had already believed in Jesus. Verse 1 talks about them as disciples, and verse 2 refers to them as those who believed.
Also, why would Catholics baptize babies?
I'm not a Roman Catholic, but I think it's because they believe baptism makes the baby a Christian.
Paul talks about baptism being an initiation in to the Christ family and the new "circumcision". Did babies have to believe before they were circumcised?
Yes he does, but he also writes about this new circumcision like this:
“28 For he is not a Jew who [is one] outwardly, nor [is] circumcision that which [is] outward in the flesh; 29 but [he is] a Jew who [is one] inwardly; and circumcision [is that] of the heart, in the Spirit, not in the letter; whose praise [is] not from men but from God.” (Ro 2:28-29 NKJV)
Circumcision of the heart happens as somebody is converted, i.e. at the time they come to faith.
As far as becoming Christians first:
To convert to Judaism in OT days, did they convert to Judaism first before they proclaimed the faith, did the water immersion (mikvah), and then circumcised?
I don't think converts to Judaism in OT times had to be baptized, but I am not absolutely certain.
I hear people a lot including Pastors that say that you have to be saved first or your heart has to be in a certain condition before being baptized and I can't seem to really find anything that definitively supports that.
I can only repeat what Philip said to the Ethiopian about believing with all his heart.