Brian, you are just having a battle of opinion; I will just answer your questions point blank:
Was pharaoh so dumb that he wouldn’t have asked “why do they need midwives then?
ANSWER: Why would he ask them this? It is plausible to think these women could still use a midwife, because you can't assume that it was the midwives ONLY job to assist the delivery of the baby. Even now midwives check up regularly in weeks after a birth. I know this, because my sister has had a midwife three times; and, if you look it up online, you can find this out too. A little research goes a long way. I don't think the issue is wether or not the pharoah in this account is "dumb", but rather how limited your knowledge of midwives is. My own opinion would be that the pharoah didn't ask such a question, because he already knew that women used midwives after their pregnancies also. The problem here isn't an errant and unbelievable Bible, it is too much speculation on your part.
How dumb is this passage asking us to believe that the Philistine’s were?
ANSWER: You ARE asking an impossible question, because any answer would be speculation. How would you prove the IQ of the Philisties. You can't. If it could be proven throughout history man has always made the most logical judgements, then you might have a case. But I believe quite the oposite would be the case. The sensible answer,then, would be to look at what we DO know about man's foolishness. Therefore, using current examples IS logical.
9/11 for example, here in America. How many times do you hear of all the warning signs the government got? Why did it still happen? Is it plausible to think that the American government acted "dumb"? If a current people can be "dumb", why not ancient? Maybe the Philistines were asking the same questions, when the warning signs (Samson's hair growing back) were all around them, and they ignored them. Any argument in this area is speculation, and is not proof of inaccuracy in the Bible, but opinion.
You can keep your opinion of an errant Bible, but these examples can be taken literally. If you are ask simply "Can people be this gullible, or unsensible?", the simple answer is YES. Looking to what we know about people, even those in commanding positions today, we know this answer to be true. I would love to hear your opinoin of George W. Bush. Is he "dumb"? If you believe he is, then your question on wether a person in power can be "dumb", or gullible, or stupid, is obviously yes. It would be interesting to know how many people in high positions today, you consider "dumb".
Summary: everything you're saying is speculation, and can only be considered opinion. Stating that these stories are any more illogical than what our current lives are, is, in my opinion, false. Stating that speculation is EVIDENCE, is false.
I don't claim that I know everything; but the FACT is that your OPINION is not EVIDENCE.