Your mash targets seem adequate although i've read the strike water should be closer to 170. How long are you fermenting? Fermentation continues for days even after the bubbling stops. Ferment for @8 days in a primary then rack to a secondary for another 4 days. Also, I've found better...
How long is your boil? If you boil to target OG and then add 3 gal water, you're essentially diluting your wort. Go buy a 7 gal aluminum pot at your local Big box HI stored for @$30-$40. Brewing full batches makes it easier to hit targets.