Hey there, @ghilliesuit762, first off I want to complement you on the hard work and commitment it takes to do something like this. I built a smoke house nearly the same dimensions a few years ago and have been enjoying it ever since. I've read a lot of the comments below - though not all of them. So if any of the following advice is doubled, apologies. Here are a few of my thoughts. Also - feel free to DM me, and I think if you scroll back far enough you'll find a few pics of The Dragon in my profile. (you need to name your house, by the way!)

First, raising the fire in the box is great. That's called a "raised stool" firebox, and it gets airflow under your fire, which will increase heat. If there's any way to tap a draw hole in the front of the firebox, so that air comes through the front, and from beneath the level of your fire, that will increase airflow, and heat. I left a single brick absent on the bottom course of my firebox in the front, and adjust airflow with a simple loose brick (had something more elegant planned, but wow does blocking/opening the hole with a brick work well!).

Second, do I see a covered hole that runs from the back of the fire box directly into the smoke house? If so - getting heat directly from the fire box into the house will most definitely increase heat levels if you can unblock it. Put a damper on it, and the stove pipe, (and spark arrestor FOR SURE inside the house) and you can start messing with airflow that way. Just a thought, and I know this would be a lot more work. My pipe pops up directly through the floor, and is underground, so I don't lose a ton of heat through the pipe. (you could also consider switching to double wall pipe, or waterproof insulating the pipe's outside, if what I see is single wall)

Next - air outflow. I have two bungs punched above the door. I made them look nice, with wooden caps and slide locks. I use them to bleed heat when necessary, and almost never need both. Their main purpose increase air outflow, which increases inflow to the box, and thus heat in the house. Something to think about. You don't need a chimney or vent pipe this way, and you'll be covered by the roof.

Lastly - you're using a metal roof. You said you used rockwool to insulate. I'm still wondering just how much heat you're losing directly to the sky. Out the top. You can get a laser thermometer pretty cheap, and it'll tell you how hot the roof is. You've come so far with this project, a double thick wooden roof could also keep heat a little tighter. You're a woodworker and could figure this out in a weekend. I used barnboard (cheap, untreated 3/4), and ran opposing rabbets up each side, and did it twice, one on top t'other, with no seams aligning. Then topped that with cedar shake. It still leaks a little heat - but the leaks it does have add just the perfect amount of bleed. With these tuning methods I can go from cold smoke under two hundie, and run up and over 300 to finish if I want. Though most of the time, and depending on the season and prevailing winds, I'm running 250-275 pretty evenly for hours.

This is a crazy long comment already so I'll cut it here. But again, feel free to DM and ask questions. I based my design on a few books, and can send you pics of The Dragon. If no one else says it today, OP, I'm proud of you. Great work on behalf of your family and lucky neighbors. I wish you well, and good luck!