Name That (Grape) Disease

So I'm in my first real season of growing these grapes, and I swear that EVERYTHING I see I assume is something terrible and horrible that's happening to the grapes. Budbreak I thought was a fungal infection. When the grape flowers formed I thought those little grapes would never grow. Here's a few more specific conditions that I may or may not have diagnosed:

1. RED LEAVES. It sure seems like they have a simple case of Autumn - however I started seeing this in June-July! We had some early heat, and I'm still figuring out water, so I'm going to guess this is water stress, or possibly a mineral deficiency, and not a more serious disease I've read about.

2. BLACK SPLOTCHES ON CANES. See the black splotches on the vines themselves (in this first picture)? Looks like a splatter of black watercolor. I've been told this is a variety of things; the one I trust the most says it's a sign of powdery mildew (a.k.a. "PM"). County Ag department disagreed, however, so I kept doing preventative measures but nothing to eradicate.

3. THIN CLUSTERS. Clusters are supposed to be think & bunchy & all that stuff, but some of mine looked half dried off, thin & scraggly. I'm pretty sure this is a result of my 'tough love' watering plan (watering infrequently, but long, such that they develop nice big tap root down into the ground). I've later heard, and read, that this watering plan rarely works on our side of the hill. Sigh - back to more water. Let's hope for lots of rain next year!

4. SPIDER WEBS OR POWDERY MILDEW? After all of the things that *could* indicate PM (powdery mildew), the major one is a 'white powdery or dusty appearance'. So this definitely defines webby, but I never saw anything powdery to go with it. And I saw a spider in one of these. Treated for PM with Kaligreen (potassium bicarbonate, like baking soda but bound with potassium instead of sodium), which is all the rage among backyard grape growers in our area.

I need to keep reminding myself that these are plants and they're pretty good at growing & reproducing on their own. So I can't mess them up too much, right? Right?