Problem is simple, BAD AIR. Seriously, your issue is with the air adjustment in part and your burn pot for the other. You need to tweak the combustion air to maximize the burn. The flames should be closer to the somerset burn look, but don't expect to dial it in exactly. Add a little air to the combustion at a time and see the effect.
The crooked flame is likely a result of your burn pot not quite seated or an obstruction in the air way. This generally in my experience is because the holes in the burn pot are plugged, or blocked. Pull the burn pot and clean the heck out of it, Brush, scrape, soak, burnish, whatever. Then take a twist drill bit about 1/64th smaller than the holes and ream them out to the max. Don't use the drill, just the bit. clean where the pot mounts carefully and look for cracks or breaks, Reinstall and do the adjustments above.
The changes in the stove are from the changes in pellet brands. Nothing that is seriously wrong, just needs to be re-adjusted.