Metal Roof Workmanship on New Home

I closed on my new home in the Phoenix area last May and I'm having some roofing issues and I'd appreciate a second opinion. Toll Brothers is the builder.

We had a leak a few months ago and they tried to repair it. First they smeared the white sealant all over it (first 2 pictures). Then I told them to remove the sealant because there's no way that's an acceptable repair for a metal roof (or is it?). The last picture is as it is today with most of the white sealant removed. I don't know if the leak is fixed or not, we haven't had a lot of rain.

Here are my questions:

1. While I'm sure applying sealant to a metal roof may prevent leaks, is this considered a professional, legitimate repair by any standard? And are there any standards about this that I can refer to?

2. In the final photo, you can see that the end "panel" was cut short so they laid in another piece and caulked the vertical seam. I don't know if this caused the leak or not, but is there any standard by which this is acceptable workmanship for a new roof? I can't imagine the caulk will last that long and it will become an issue down the road.

3. You can see in the one photo that a smaller amount of white sealant remains midway down the roof where it meets the stucco wall. Is this a proper way to design and waterproof that roof detail?

4. How is the color applied to the metal typically? Is it paint, anodized, or powder coated? Is it common to paint metal roofs to hide repairs like this?

My builder is saying that Arizona law states that they have an opportunity to repair rather than replace the roof. My argument is, from my layman's perspective, this is a workmanship issue not a repair issue and that it should be redone correctly like it should have been to begin with. Am I off base here?

In my mind, I just don't see why you would ever apply sealant to a metal roof. They say that they will paint it so it matches but IMO it will look like crap. I'm puzzled that Toll wouldn't go back to their sub and make them make it right. One guy who was looking at it said that to replace the end panel they'd have to replace all of the panels.

Thank you Todd. Is there an industry standard I can cite regarding the spliced piece? I'm convinced this will lead to a problem down the road as the caulk will not last as long as the metal will.

I understand what you're saying about the sealant but in this application it is unsightly, even if painted to match the metal. Is there a workmanship standard that says that a brand new roof shouldn't have sealant? I get that's how you might perform a repair, but to install a new roof and require sealant at the beginning of the roof's life seems more like a design or construction defect.