Yes, you can use AP, and of course better flour has a tremendous affect. My go to is a 25% whole grain hard red wheat (I mill my own) with 75% Organic commercial AP. I have a very old starter. Hydration is key and how you add the water. Baking is a two step process, one/half with steam and covered crock, the former uncovered with no steam.
The photo shows a bread that I prepared for a neighbor that has 84% hydration and a 24 hour final rise. It is a whole grain starter and the main dough is pillsbury AP (I am out of my go to King Arthur Organic AP). It has flavor to kill for.
Another key is if you use yeast, you must use it properly. Active dry yeast must be proofed and combined with the wet ingredients. Instant yeast (which I prefer if using yeast) is simply mixed in with the dry ingredients. Just practice to get it right.
And one last thing, use baker's percentages. Once you learn baker's percentages you can far better understand bread baking.
