As a contractor I can tell you that most reputable contractors probably don't need your job, and if you make things too complicated or troublesome, they will move on to other jobs that don't throw up red flags. Much of what you ask for here is reasonable, but bringing a second contract into the equation can set of some alarms that you may be a difficult customer to work with or even a litigiously minded person who is likely to try and bring a lawsuit whether deserved or not. Anything you want covered should be in the original contract.
I acted as general contractor and did all my own demo to remodel my 6x8 bathroom. I hired subs individually to do most of the work - an electrician, a plumber, a drywall guy and a tile guy. I painted the walls and the ceiling. I replaced everything except the cast iron tub. Materials and fixtures cost around $2000 and labor was about $3000. My subs had no problem with me supplying the materials, because I discussed their job scope in advance. This project took 6 months but I did have another full bath to use in the mean time.
The best place to start with any remodeling project is the budget. Not only will it have a big impact on the type of materials you select for your bathroom renovation, it will also help you set the boundaries of your design. Knowing what you can really afford to spend will make it a lot easier to decide what items you want to replace and where you need to get creative!
I can't even get anyone to look and give an estimate to complete a bathroom remodel- just the bathtub/shower part has to be done as the last person who was doing it died- the rest is complete and have all the items and materials already and paid for. once they hear that they are no longer intrested- what do they expect? me to let them rip out what was already done and repay and redone everything all over again so they get more money? and throw out brand new imported Travertine and Spanish tile?
I just renovated a 6X12 bathroom. Old cast iron tub removed. Removed and saved existing vanity and vanity top. Removed the toilet and replaced the existing rotten flooring and added on to the existing partially rotten floor joist. Removed the drywall and tile from around the old tub. After the new flooring was in I had to modify the existing plumbing to accommodate the new tub and shower surround. The hot and cold water lines had to be raised to fit the surround because the new tub is taller and the drains had to be installed and moved to fit the new tub. Drywall was finished and painted. New faucets,New tub,Tub Surround, and flooring materials were purchased by the home owner. Labor cost was 4,584.00