I don't think you will get a definitive answer because there is none. Machines and gages will never be true on, from one, to the other.
Personally I rely on my miles traveled more then the BC and the fuel gage. Old habits die hard I guess.
I also would say that unless you are running a fuel additive I would never let it get below a 1/4. I run mine into the Idiot Light on Sea Foam and Marvel gas treatments. Other then that, I top it off pretty regular.
Maybe the way I was brought up but running tanks low is for sure harder on the fuel pump and yes I too believe you can suck dirt past a fuel filter into the injectors.
I have seen the difference that flowed and cleaned injectors make in performance and know they got clogged someway. I proofed it on a live data recorder/fuel controller that showed both injectors, flow, pulse width, open and close, and the affect on AFR. With before and after data side by side.
I wish I knew all the specifics on these injectors. Marren Fuel Injection http://www.injector.com/
would have tested and flowed replacements, and I know they will test, refurbish, and flow your injectors for a reasonable price, on a pretty decent turn around. Not Affiliated, just a satisfied customer.
Run your tank the way you want but rely on miles, not the BC, to keep you from huffen and puffen the LT down the road