Eagle Pack's fish formula in its day was the best kibble going; it was the only kibble containing fish meal that got a permit from the US Coast Guard so that they could use fish meal not preserved with ethoxoquin. However, since 2007 when meat based, grain free formulas became available, it is no longer a food that I recommend. Even though you are adding fish, the grain level is too high; most grain containing kibbles average 60% grain. Their holistic food not only contains the high level of grain but the meat portion is not based on the ancestral diet of the Newf.
Also, you should not add a liquid multi-vitamin; any properly balanced feed will have the appropriate vitamins. Supplements can help but they should be specific, not across the board.