Aliboo, I don't know if I can offer much help but I can definitely sympathize with you. Maddie does the same exact thing. She is great in the morning first thing and does her business quickly outside. 3-4 pees and a poop like clock work. About an hour or so later though and she has to poop again.
We solved that issue by covering the whole area she's in with plastic under newspaper and a pee pad on top of that. That way when she misses the pad she doesn't wreck the floor.
As far as the excessive peeing is concerned, I wish I knew what could stop it quickly but I don't. Here's what we have been advised to do by the trainer.
1. Limit her food and water intake. Not a diet but feed her three times a day and leave the food down for no more than 30 minutes. Give her water at the same time. Remove the water except for meals and after physical exertion like play time. In the heat of the summer you need to be careful about this part though. Limiting food and water to specific times should at least keep her from having to go all the time.
2. Limit her range. Our trainer suggested keeping her tethered to us but that is very incovenient. Instead we try desperately to keep in in sight 100% of the time and in range of a quick scoop up. This way when she does try to go inside we should be able to catch her and discourage her. This is the part that's tough because just saying no doesn't startle her enough to stop. We have to clap sharply and yell no. Then we pick her up and take her outside to go.
3. Reward for going outside. We say "do your business" when she squats and exclaim "Good Girl!" (as excitedly as we can at 5:00 am) when she's done and give her a treat. So far she knows she gets a treat when she goes and I think she knows she's not supposed to go inside.
Right now I think she really needs a signal to get us to take her out. I have heard that you can teach the dog to sit and speak and once you have that down you do that in front of the door every time you take them out to go. After a while they will associate sitting and barking at the door with going out to potty. Nice theory but We've yet to get it down
Tom