Elizabeth, your explanation is not making sense to me. According to your response, commercial food delivers balanced nutrition in every bite, and raw provides balanced nutrition over time.
This doesn't change if both food sources are included in the diet. The cat is still receiving balanced diets from the commercial portion as well as the raw portion. As long as the cat is not overfed or oversupplemented, and as long as the raw portion of the diet is properly balanced, there should be no overdosing of vits or mins in a commercial/raw integrated diet..
Perhaps. However, given that cats are able to assimilate the vits/mins in raw food differently than they do in cooked food, and that the vits/mins that are in cooked/processed food are not from species-appropriate sources and are added after the fact, I'm just not sure we can be sure about that. It may be fine. I, however, am not going to recommend it b/c I think it's a bad idea for many reasons, not the least of which is that it kinda seems pointless.
As long as the cat's GI tract is still being inundated w/ species-inappropriate food, the GI tract will not work well enough and may fail to assimilate adequately the nutrition from either source--this is obviously a more significant problem for IBD cats, but I have a hunch that most commercially-fed cats have IBD to SOME degree due to being fed species-inappropriate food, and IBD=malapsorption.
So I guess what I'm saying is that IMO it's a bad idea b/c the cat may well not get much, if any, of the benefits of raw while also being feed commercial food. We know how commercially fed cats do; we know how rawfed cats do. There's not much, if any, data on how half and half cats do, and the experience of those on the various raw forums suggests that since symptoms of IBD, etc. do NOT resolve until the cat is 100% on raw, there are good reasons, many of which concern malapsorption, for not doing this.