I had a crappy pellet stove years ago that had a lifting auger, and it would jam up on wood pellets semi regularly. I fiddled with it and eventually realized that the reason it was jamming up, was because the auger was fixed on both ends. I cut it down so it was fixed on the driven end only, and never had a jam up again, not even one. There was a little slop in the fixed end, and a sloppy fit on the auger inside the tube, this allowed for some movement. Whenever a pellet got between the OD of a flight and the tube, the auger would deflect and keep pushing pellets eventually cutting up the stuck pellet or bypassing it. I would notice an occasional "blank" or near empty flight when feeding, but that was not a problem. It moved a lot, constantly actually, but worked great! This auger is an exact copy of what was in that old stove, a sloppy, wobbly, standing auger fixed driven end only. Hopefully it will work just as well.
Feeding from the hopper may be an issue, I may revise the geometry of the hopper and tilt the whole unit to ease entry and exit. Vibration and stirring could be incorporated if needed. I'm going wait and see if it makes gas before I go too hog wild.
What do you think the chances of this design actually making decent gas? I'm a little worried that the char bed won't build up, or last as long as I hope it will. What happens is the char bed is minimal?
If the char bed becomes the issue, I don't see it ever working unless I Pelletize as you mentioned. I'll probably make a big set of nozzles and try it out on pellets for it's maiden voyage, that will slow things down a lot, and if it makes good gas, then at least I know the design works.