I only read Jo's response...and we did the same thing in our house. There are rules to be followed and guidelines to be met. The kids need to know their boundaries.
Even with no naps, BOTH of your kids need an hour of quiet time in the afternoon. That could be watching cartoons, reading books, sleeping - whatever as long as they do not bother you for that hour unless it's an emergency. My kids will be 6, 8, and 10 for this summer and that rule still stands for my sitters - everyone needs a break. We do it on the weekends also if we are staying home all day, which rarely happens.
Explain to your 5 year old (she is old enough) that if you are driving or on the phone, those are not appropriate times to talk constantly. The complaining like you describe doesn't sound so much as complaining, as her trying to take control of her life - normal for this age. Tell her there are certain things she has choices in (outfits, fruit or veggie for lunch, what cartoon to watch), but there are things she does not have choices in (getting dressed, eating her meals, and taking quiet time) - just some examples.
Make a rule chart - kids love this. Our sitter had to do this last year with my kids because they were giving her a run for her money. When they broke a rule, they would go look at the chart and find the consequence they decided would fit that infraction, and they took the punishment (5 minutes sitting out at the park, age time in their rooms, napping instead of staying awake at quiet time, whatever). I think this will work especially well with your daughter since she wants some control.
Also, give her a chart of HER responsibilities every day. She needs to wake up, brush her teeth, brush her hair ,eat breakfast, get dressed, shoes on, use the bathroom before leaving the house, etc Get some cheap star stickers. Give her a star for every group of tasks she completes without arguing. When she has 25 stars (or however many) give her an extra 15 minutes at the park, ice cream, an extra book at bedtime, more M. time, whatever.
As far as the 2 year old, she should be sleeping through the ngiht now. Find some books or talk to a doctor about her not sleeping through the night. If she is waking up AND not napping, I can only imagine how fun that kiddo is when things don't go exactly as planned...2's are fun even when they get enough sleep.
But if you set these rules with your 5 year old, the 2 year old will grow up from a younger age knowing them and follow in line. Your life will be easier.
Also, sorry this is so long now, but your husband HAS to help more. I don't care if he works, so do you. If the kids are driving you this insane, he has got to help more.