TLDR - Everyone is awesome - Heather, Kevin, Joey - A+++ Thanks so much!!
While it was such a headache to deal with my warranty company and try to get them to honor their contract, the silver lining is that's how I learned of Fix It Services and ended up using them to replace my hot water heater without using the warranty after all (grr).
I have nothing but great things to say about everyone we've dealt with. The first technician who came out to diagnose the issue, Westin, was polite and quick to do what needed done and refer back to the warranty company.
We ended up having some other technicians come out to give us a quote on the repair outside of warranty, and that was Kevin and Joey. They were fantastic. They took their time to answer our questions not only about the water heater but also about some water pressure concerns we had, and even talked about our water softener. They were very friendly, funny, and knowledgable. They did not mind spending time talking to us and swapping stories (and no, not because they were being paid for every minute they stayed either... lol).
While we still tried to sort out our warranty issues over the course of a few days, Heather in the office continued to be such a delight to work with. She understood all of our frustrations (as did Kevin & Joey), worked really hard to be an advocate for us with the warranty company and dealt with a lot of back and forth phone calls and questions of both my husband and I while also dealing with the warranty company. Every single time we spoke to her she was polite and friendly, truly sounded eager to help and was not once bothered with us when we kept having to take some more time to decide how we wanted to move forward. - She did everything she could to swap schedules around and keep the technicians available for us as soon as possible, as we had already been without hot water for over a week.
Kevin & Joey came back out to do the job, after waiting around on us for awhile to make the decision this morning. They were just as friendly as before, and were super efficient and professional in getting the install done correctly and quickly. They answered some more questions, provided some knowledge on flushing our system, tested our water hardness for us, and provided an estimate for a water softener. Every step of the process working with this company was a breeze and that's not easy to say about a lot of companies and contractors that are "randomly" assigned by warranty companies.