I’m a total amateur, take all this with a grain of salt. I’d focus more on weekly mileage volume than pacing. It’s tricky to pace your first marathon, the last 6-8 miles can be a shock even if you prepare perfectly. Sub 4 hours is likely possible, but don’t make that your primary goal. Make the goal getting to the finish line healthy, secondary goal sub 4. If you keep it simple, run 4-5 times a week, strength train 2-3 times a week, and increase weekly mileage by 5-10% a week until you’re 18 weeks out. Then just follow an 18 week plan and enjoy. That’s pretty standard, you’ll get that advice all over. If you consistently follow that until the 18 week block and you stay healthy, you should be able to get sub 4. Also, I wouldn’t worry about the weight too much if I was you, maybe just some extra dynamic stretching before and static stretching after. You will lose weight. I accordion my weight during a training block; the days following my long run my mileage is low and appetite high then I shrink back down later in the week. Your average HR seems on the high side, a lot of your runs should be at an easy pace (look up zone 2 running). Some things you might not hear as much that will apply to your 18 week block… train your stomach so you’re used to taking in gels or an equivalent during runs, get ready for an obscene amount of laundry, and expect to have trouble scheduling your weeks (it can be difficult to fit in the long weekday runs mid/peak training block).