OK - read through your other thread. We need to clear up a couple of terms.
With respect to a GARN, which is all I have experience with, a "burn" for me is the amount of time I fire the unit to raise the storage water temperature from wherever it is, to whatever I want it to be. That could be 130-200, 150-180, etc. It may take 1 or more burn CYCLES to get the desired temperature rise. A single burn cycle is, in my own little world, a single load of wood that is consumed. You do not "stoke" a GARN, and you only reload after a cycle is largely complete. I do not always need to reload, but if I do I wait until the flue temp is down around 200-250 F.
A load of wood in a GARN will burn down in anywhere from 45 minutes to 2 hours, depending on density. The temp rise can be anywhere from 15-30 degrees over the course of a burn cycle. There is no way you can get 1M Btu's in a single burn cycle (single load of wood). Based on your estimated heat load, you can easily get by on two burn cycles in the AM, and two in the evening. Even with your "bad" wood.
The total amount of time taken up for the entire days heating effort should not be more than 15-20 minutes. Seriously. I am in the same boat you and most other people are with respect to time demands. Wife, kids, job, blah blah. For a very high heat load day (35-40k Btuh), I get up at 5AM (my normal hour to get up), throw a load of wood in the GARN and light it. I go back in the house, eat breakfast, take a shower, make my kids lunch, make my lunch, and do whatever other morning chores I have to do. Before I leave for work, about 60-90 minutes later, I throw another load of wood in the GARN, set the timer for 90 minutes or so, and leave for work. I do not watch, babysit, or otherwise stick around to tend the thing. It is dead simple, safe, and easy. In the evening, if I feel the need to have another burn, I will repeat the process.
You will NOT be able to burn 16"x48" rounds in a GARN. I burn plenty of low density wood in my GARN, and I still split my pine rounds down to 8-12"x20". Oak and other hardwoods get split smaller. The GARN will burn most efficiently if you can the fuel to burn completely and quickly. You should NOT completely pack the firebox solid with wood. I also burn PLENTY of "less than desirable" wood that is punky, but dry. I am AMAZED at how much energy this "bad" wood still has in it. Certainly not the same as a load of nicely seasoned hard oak, but it is certainly worthy of the effort to get it in the fire box, IMO.
You may well be able to find another system that can develop the heat output you want, but I cannot make any suggestions because I am unaware of them. I have repeatedly checked and confirmed the GARN WHS2000 input rating of 425k Btuh. With good fuel I actually exceeed it by 5% or so regularly. That means with a 2000 you will need 2-3 hours of firing per day to meet your 1M Btu/day goal. This HAS to be more reasonable than the amount of effort, and fuel, you are putting into your OWB.
Hope this helps.