First, it is rare that parents ever agree on parenting 100%. If they do, it is because one gave in and just figures the other will handle the responcibility.
EX1: Kids will always pick their favorites. It is usually the one that will let them get away with more. They go through phases. At one point, they side and love the one that will let them do as they choose. Then another point, it is the one that disciplines them. That love comes from the respect they are giving you from being their parent. Since the child is 5, they are at an age where they will size up the parents. If the parents do not work as a team, for the most part, they will break you down. This has to stop at an early age, or teen-age years are going to be absolute hell for you. Sit down with your husband, calmly and respectfully with out judgement or agruement, come up with a list of rules that should be taught to all of your children. Agree on a set rule for each catagory. Ex: Bedtime, dinner time, play time and such. This is a difficult thing to do, but well worth it.
EX2: Totally normal. My youngest is two and has been throwing fits since she was in my stomach. Some kids are easy and rarely throw fits like my 7 year old. Some are outrageous, and require more attention. When the fits start, get down at eye level and calmly tell them to stop. They won't the first time, so get down at eye level again and give them the gritting your teeth "stop it" tone. Let them know you're more serious that time. It might stop, but I doubt it. Third time, hold their hand, get down at eye level again, and say, this is the third and final time I am going to ask you, I wont be nice if I have to say it again. So stop it, and act like a good little lady/boy, and let's finish what we are doing here so we can go home and you can play with your toys. By doing this, they 1. know that they get three trys at your patience. 2.know that you are respecting them enough to warm them. 3. know that if they follow your rule, they will be rewarded. It will take some time to enstill this in them, but it is well worth it. My 7 year old doesn't go past two times. She sits patiently and is polite.
EX3: Every child goes through being afraid of the dark. And until she reaches and age where ghosts stories are no longer cool to tell, she probably will still be somewhat scared. I'm still a little scared of cetain dark places and I am 28. Get her a cool little night light that she picks out. Let her be the one to turn it on. HAve her read a book to calm her mind down before bed. This should work after a few weeks of repeting.
EX:4 Get her a cheap little step stool from walmat. Preferbly a white one she can decorate. Give her markers, glitter, what ever floats her boat. Have her decorate it with all her own ideas. Call them big girl designs. Put it next to her bed, and tell her that when she wakes up to hop on the big girl/pricess platform and say good morning! With another baby on the way she is going to do anything to stay your little baby. So let her be that from time to time, but make it more exciting to be mommy and daddies big girl helper with small chores.
Sorry for the long ramble, but I hope this helps out.