"Oil is a fundamentally global commodity. Gas prices are not going to drop just because the US produced more oil."
If the US produces enough oil to have a net increase on World Oil production then yes the price of oil will go down. And as far as the price of gasoline, currently the US is refinery constrained, so we need to build more refineries and that coupled with a decrease in the price of oil will drop the price of gas.
"And unless the US decides not to sell or export natural gas and shift over its energy sourcing to predominanly natural gas (no less revamp transportation and infrastructure to suite it), there is unlikely to be much change."
It's extremely expensive to export natural gas, generally you have to liquify it first, which adds a substantial amount to the cost. So, I think you are completely wrong about this. I think one of the best approaches the US could take would be to aggressively convert our over-the-road diesel trucking fleet to natural gas. This would act to substantially replace a large amount of imported oil with local natural gas. Couple this with using strong hybrid commuter vehicles (that can go dozens of miles off of battery power alone) and the US could be energy independent. Or at the very least, avoid importing petroleum from outside of North America.