It's important to distinguish church disciplines from church dogmas. Many of the church disciplines, like having the mass said in Latin, have indeed changed with time. But dogmas don't change.
http://www.saintaquinas.com/controversial.html
1. Some (conservative) Anglican and some Lutheran priests/ministers that decided to leave the (increasingly liberal) Anglican church and become catholic priests were married (as anglican priests) and some had children. So now, they are indeed married catholic priests with children. They have a lot of responsibility. It's very hard to serve both your congregation and your family. A catholic priest is "in persona Christi", representing Christ, they are asked to identify with Christ by being celibate (and being male). They are considered to be married to the church.
But priestly celibacy is not a church dogma, it's a discipline. That's why exceptions were made for the anglican priests. Technically, it can change, but the church believes as St. Paul does, that it's better not to have divided commitments.
2. No. Again, it's because a priest represents Christ to us. He is acting in persona Christi. It's not because the church wants to exclude women. In fact, young women are joining the more orthodox religious orders in record numbers these days.
Here's some light reading to learn more about points 1 and 2:
http://www.ewtn.com/library/PRIESTS/ORDAINED.TXT
In it, it states that the church has no authority to ordain women as priests because of the example of Christ and the constant teaching and tradition of the church.
3. No. Because marriage is meant to be both unitive and procreative. Birth control blocks those purposes. Plus, it is possible to have break through ovulation on hormonal birth control, leading to a chemical abortion when a fertilized egg meets a uterine lining that has been artifically thinned, making it unable to sustain a pregnancy.
4. I think they need to do a much better job at cathecizing. We need better RCIA programs. I'd like to see adult cathecism classes for those of us who survived catholic schools in the 70s and 80s and their poor level of instruction in the faith. Better sermons, too. Priests should preach what we need to hear, not just what we want to hear. They also need to foster more of a sense of community at church, especially the larger parishes.