Very fustrated... few problems trying to bake sourdough

Practicing baking sourdough and have a few problems.

I am attempting to get the tangy flavor of sourdough, so I have been retarding dough overnight in fridge.

Problem 1. Every time I retard the dough overnight in fridge, I get no oven spring.

• In banneton, The dough rises overnight nicely upon taking it out of fridge,
• Allowing dough to warm up for an 1.5 hour before baking, but no oven spring.
• My loaves look rather flat with pathetic crumb.

Problem 2. Crust looks very blah and dull.

• My idea of a nice crust has a reddish orange, slightly shiny, blistered crust. 

Problem 3. Even after retarding dough overnight for 12-14 hours, still no tangy flavor.

Baking in lodge cast iron combo. I've tried baking at various temperatures.

 This loaf, oven preheated with cast iron at 500 degrees. Put dough in and reduced to 450 for 20 minutes, remaining 10 minutes with no cover at 475 degrees.

Using this recipe at http://www.thefreshloaf.com/handbook/san-francisco-style-sourdough

White flour: 100% (except starter which was  80% white and 20% whole wheat)
Salt: 2%
Water: 72%
30% of the flour is in the starter. (I’ll give two recipes, one for starter at 100% hydration and another at 60% hydration)

Ingredients
White flour: 350 grams 
Salt: 10 grams 

Water:

• Using a wet starter: 210 grams

Wet starter:

• about 100% hydration 300 grams  (starter was fed night before)
• Starter was 80% White and 20% Whole Wheat

My loaf...