A customer who I have worked for in the past has requested an estimate for some tile work. I have done some tub surrounds and floors in the past but not enough to develop a feel for working up a fair estimate because I really don't know how may hours it took me in the past due to mixing it with other work on the projects I was working on. I try to search up this info but the forums I locate and especially the responses don't do a good job of specifying just what is included in the times for the different scenarios that they are talking about, not to mention that some of the times discussed seem unrealistically low. For any bid, I have to allow a little extra for time lost to murphy's law.

This is all new construction but they installed drywall to the tub and shower surrounds so I'm tearing out to the studs and replacing with cement board as specified by the customer. Time I might spend picking up materials and such I can estimate separately.

Scenario 1
An ordinary three sided tub surround about 6 feet high above the top of the tub. This is a backerboard and mortar job, not a mastic adhesive job. The tub is properly located up against the studs this time. I need to:
a] install a tub protector of cardboard & packing tape .
b] tear out the existing drywall.
c] install additional bracing lumber where needed between the studs.
d] install a moisture barrier to the studs.
e] install cement board.
f] tape the seams with thinset.
g] tape & finish the joint between the cement board and drywall with setting type joint compound.
h] install 8" square tile using thinset and leveling plugs, cutting tile as needed.
i] grout.
j] caulk the tile edge to the drywall with the caulk that matches the grout (customer's preferance).
k] remove the tub protector & clean up.
How many realistic hours might that take, not for someone who does only tile tub surrounds every day, but for someone who has done several on an occasional basis over the past years?

Scenario 2
How much additional time would be added if I have to install a recessed prefab tile-ready square insert for soap and shampoo into the backer board and tile into it?

Scenario 3
How much additional time if I have to lay out and install a horizontal contrasting trim stripe into the tile of different tile width and height?

Scenario 4
Same as Scenario 1 but it's a three sided stall shower with a plastic pan that does not get tile.

Scenario 5
There are three bathrooms and two foyers that get flooring tile. Again, the floors are a mortar and backerboard job. I'll be screwing down 1/4" cement board over plywood with mortar underneath and installing the tile with thinset.
Is there a square foot cost for installing backerboard and tile to floors with thinset that I can apply to work up an estimate, considering that these are smaller irregular shaped rooms with closets?

Scenario 6
How much might I add to the flooring in these bathrooms rooms if they want a boarder pattern stripe spaced in a few inches from the wall? These are not just simple rectangular rooms. Some have at least one rectangular inset or outset on the floor.

Again, I have done this before, I am not a rapid tiler who just does tile everyday and I work at a careful steady pace. And they want the job priced, I think more so they know what they are getting into, not so much because they are shopping everybody for the lowest bid.

Thank you if you can share any experience with this.