What's interesting is that the previous dishwasher worked fine, but all the plastic parts inside had become brittle and were breaking, and at the same time some things transpired such that a family member offered us this new-in-box dishwasher. IE: point being that the previous dishwasher didn't have this food splattering problem.
When the repair guy came out, he commented that the garbage disposal hadn't been properly installed (10+ years ago) and that it might be part of the problem. In theory he fixed that issue, and we assumed that might also have been the problem. But, with it back to spewing food bits everywhere it seems unlikely that was the problem. The level issue you point out is perhaps worth experimenting a bit.
The bits of food makes me think it's the garbage disposal. Is there an obstruction in the hose to the garbage disposal and/or some obstruction in the garbage disposal itself? Got any kids? Maybe you'll find a missing Lego piece!
When the repair guy came out, he commented that the garbage disposal hadn't been properly installed (10+ years ago) and that it might be part of the problem. In theory he fixed that issue, and we assumed that might also have been the problem. But, with it back to spewing food bits everywhere it seems unlikely that was the problem. The level issue you point out is perhaps worth experimenting a bit.