So my spin on this has some similarities.
My favorite phrase to people who envied me for my ability to travel for my job was, "It's fun, unless you're the one doing it". Business travel is most cases is not enjoyable. You are not going there to sight see, you are being sent there to work. As such, they usually want you on the road as short as possible and in the client's office as much as possible, so I would leave the hotel early in the morning and get to the facility, then spend a full day, go get some dinner and then spend more hours in the hotel finishing up all the other e-mails and work I had missed back at the office to then go to sleep and do it again. I did 50% travel for a while and 25% travel and it can be managed, but it is not fun.
I've also worked for European companies, British and German ones, and it is crucial to understand that their expectations versus US expectations are vastly different. You need to dig heavily into that before you take an offer or you may be in for some unpleasant surprises. British companies are notoriously frugal (read cheap) and traveling on their dime is like the worst travel movie you've ever seen. At times when we traveled together we were asked to share hotel rooms with colleagues. Also are you not a W-2 employee? The $7500 for health insurance is what throws me. Are you a contractor of 1099 employee and they do not provide you health insurance through the company? Do you have health insurance at your current employer?
I'm a certified PMP, so I get project management, and I'd say it's highly likely that a 50% travel PM is not much shy of 24/7, so you may be fooling yourself thinking you are getting away from that. I work in IT as well, and my general statement to anyone who grumbles about the 24/7 and being in IT is that you got into the wrong field then. It's a given and I'm now in executive management and I still have to deal with things at all hours of the night and I'd say I've got a pretty sweet position now, so this will not likely change for you regardless of what they are selling you to get you in the door. I was just working a problem with my team that was quite hairy until 1:30 in the morning last week.
The lack of moving up is a legitimate problem if you aspire to higher roles. That's always a trade off with one company to another. I would caution you against advice to take this to move you up the salary ladder. People tend to forget that the ladder is not infinite. Your on the MMM forum, so if you're goal is FIRE in 5-10 years then it might not much matter, but if you are looking at a longer career, jumping into the 100-130 range you expected at 30 is going to create some problems for you in the future. You end up pricing yourself out of opportunities. I just went through that myself recently as I tried to get out of a toxic culture and my high salary created issues with 80% of the potential employers I spoke with and it was not much higher than your range. Even though I told employer's I understood and was OK with lower pay, it was massively difficult to explain away. Now I did not want to relocate, but even if I did, once you start getting above $120K your prospects for positions get very slim as to how many are out there to offer that pay. If you can get one and keep one long enough to FIRE, it's great, but if things go south and you are making $150K and everything in your city pays $110K or less (which is about what a senior PM should expect in most markets outside of East Coast and CA) trying to convince people you are OK with market rate when you were getting more is a battle I'd not wish on anyone.
Finally, unlike an earlier poster who enjoyed the travel and had her hubby fly out from time to time because they had no kids, I did this with kids and you said they are in your near future. That much travel with kids is a totally different animal. I had a resentful spouse at times because I was heading out of town in the middle of a house full of sick kids, or some other drama. I would not downplay the stress work travel creates at that level, especially being gone on the weekends if your spouse also works. You now are taking away time you had together and with kids it may be the only time you all have to spend as a family. That has an impact. We tried the "honey come out and join me" and with kids it basically proved impossible. Some employers even had events where spouses were invited and paid for to come out and we had to turn them down because wife had to stay at home with kids. It was not the main reason we got divorced but I promise it did not help.
ETA: Sorry I forgot this was a work at home position too. I also did that for a time. You need to make sure you have a place to work, and that your wife and your future kids understand during the day you are working. This can be hard. Also many people miss the interactions with colleague in the workplace, so again this is a "sounds wonderful" on paper, but the reality turns out to be vastly different for some.
Also as an employer looking at your resume in the future, leaving after just six months at your position shows very clearly you have zero loyalty and that still plays a spot in hiring today. After two years or so it's kind of par for the course in this day and age, but anything under that if I see a resume with someone that moves every year, and I have another candidate who did not? The offer goes to the other candidate. We put time and money into training these people and I do not have time to keep interviewing and training. We've got work to do.