Delaying Baptism

 As a Protestant who values both the declaration of 'sola Scriptura' and the wisdom accumulated by the church and often remembered through traditions, the usual delaying of baptism for those who confess faith in Jesus Christ has confused me for a long time.  As I'm reading through Acts again, I'm reminded of that confusion.

 For instance, in Acts 8, many Samarians believe and are baptized, and Simon (a former magician) was part of that, though later Peter seems to indicate that he was not really regenerate. In this place, no time between believing and being baptized is specifically indicated; they are described together without detail.  However, as far as I can find there are no clear examples in the Bible of delayed baptism. There's no let's-see-if-it's-real period. I'll list several possible ones at the end, and I'll freely acknowledge that churches stopped practicing immediate baptism very early in church history. Thus, the conundrum.

Here's the examples of baptism with a timeframe that I could find:

• Acts 2:37-41 - that day
• "So those who received his word were baptized, and there were added that day about three thousand souls."
• Acts 8:12-14 - unspecified, but rapid
• They believed and were baptized, before the apostles heard and arrived.
• Acts 8:34-39 - immediately on profession of faith
• The request for baptism was his profession of faith.
• Acts 9:18; 22:12-16 - immediately
• Paul was baptized immediately, before even breaking his three-day fast.
• Acts 10:44-48 - immediately
• As soon as the gathering of Gentiles receives the Holy Spirit, Peter proclaims their right to baptism and then commands them to be baptized.  Then, they stayed together for further instruction for some days.
• Acts 16:14-15 - unspecified, but short time
• No timeframe is recorded for the gap between Lydia's profession and baptism; but it all most of happened within the 'some days' that Paul was at Philippi.
• Acts 16:30-34 - at once, that night
• The jailer took them from jail, washed their wounds, got baptized, then served food - all before morning.
• Acts 18:8, 11, 18 - unspecified
• The text here says 'believed and were baptized'; there is no clear gap between them. However, the time is unstated. (From 1 Corinthians 1, we know that Paul baptized some of the believers during the 18 months he was there. We can assume the rest were while Paul was there also; if it wasn't, surely the wording would be different.)
• Acts 19:3-4 - on hearing the Gospel of Jesus
• Former disciples of John who had been baptized into his baptism were baptized into Christ as soon as they accepted the full gospel.

 Below are the potential instances of delay, but none of them actually state a delay.  Why is church tradition and practice so radically different from the Scriptural examples?  Also, I would be interested to hear my strongly Reformed friends' views, since the reasons given for infant baptism should be consistent with my thoughts, I think.

Possible, but unclear, instances of delay:

Matthew 3:7-9 - John the Baptizer calls for the Pharisees and Sadducees to bring forth fruit demonstrating repentance instead of coming to be baptized.

Luke 3:3-16 - John says something similar to the crowds, but here he seems to be simply describing what true repentance leading to baptism should look like.

In Acts, there are stories of people believing whose baptism is not referenced or its timeframe is completely unreferenced.

1 Corinthians 1:14-17 - In this passage the time-relationship between the Corinthians belief and baptism are unstated.

Jesus was not baptized till the beginning of his public ministry, but that is a different matter entirely.