I also use this method exclusively in the summer months in CA. Ground water temps are too high to get to pitching and I don't have a pre-chiller setup. I have yet to encounter any problems.
My reply is in regards to your last issue. It seems possible you are trying to sparge too fast and not allowing your pump to remain full. Is your pump making any strange noises while sparging? If it is, a good place to start would be to pinch the discharge back in your system. I've seen this...
You will want to get the airlock out and clean it. Make sure to sanitize before you put it back in. A better solution would be to rig up a blow off tube until the fermentation has died down.
I think it looks good. That unit should be able to do everything you need for fermentation, it has heating and cooling capabilities in one unit so you would be good to go.
Have you always mashed at 158? A temp that high will leave your finished beer with more unfermentable sugars thus giving you the higher gravity reading.
I think you are on the right track. Ultimately you will figure out what works for you and what doesn't. Until then its trial and error. I strictly used the set it and forget it method for 2 years because I was afraid of overcarbing my beers, once I finally tried force carbing and had good...
I don't swap lines at all. I don't serve at 22psi either. I think the best bet would be to force carb to desired carb level and then burp and bump the regulator down to serving pressure (8-12psi). This is how I handle all of my kegged beers.
You have a very beautiful rig!! It gives me hope that someday I too will be able to have my ideal setup. I noticed in your two pictures that the pump head orientation is different. Were you having trouble priming the pump or having cavitation issues with the inlet coming in from the top or...
I would partial mash the grains over adding more DME IMHO. I prefer to have some control of flavor and color in my brews. My post was never meant to deter you from using the grains, only to clarify that to get the most out of your current grain bill it would need to be mashed. You could...