A punitive approach to what could be unforseen and atypical delays may be a bad idea. I would suggest offering a bonus for the job being completed early rather than a penalty for it being delayed. If material is ordered, we can't make it arrive faster if something delays the shipment. We recently ordered a bathtub requested by a customer. It was promised by our supplier for a Wednesday delivery. Bad weather hit Texas and it just didn't leave the warehouse until the following Monday. It blew up our schedule for the project and it wasn't anyone's fault or mistake. If we have an employee critical to the project get sick or injured, we may not be able to get things done as originally scheduled. Jobs can get off schedule for a lot of reasons outside the contractor's control. Charging them for those things is likely to turn them away.
I agree with everything you said. I think the trick is to convey those concerns when discussing what work will be needed. Everyone will have concerns but if you come across as too needy or pushy they may think you will be a pain in the butt homeowner. I have seen this before where you have to come back 3 or 4 times for something not dealing with the work, but you are trying to be polite and helpful for business. Word of mouth is the best way to get more buisness, in my opinion.
Any contractor or subcontractor who works on your house should be bonded, licensed, and insured properly according to state and local standards. Insurance can help protect you if your home gets damaged during construction or workers are hurt on site, while hiring a bonded contractor can help protect you if the contractor fails to pay workers, doesn't pay for permits, or doesn't finish the work. Here's more on how to do your research.
Bathroom remodels provide 60 to 70 percent resale returns as a home improvement project. However, this project isn’t cheap. It is essential to plan your remodeling ideas ahead of time. Then, hire a remodeling contractor for the job. Ask questions, set realistic expectations, get accurate cost estimates and budgeting from the start. Also spend time learning how to work with a bathroom contractor.