Dustin,
I am pretty new to all of this so take it with that in mind. We bought a Scribner jug so it would not be confused with the regular gas can. It has a hose and is square. Part of choosing that brand was you can get replacement parts. Clear jugs are not best for storing fuel if sun light hits them.
You can get a normal fuel jug pretty cheap. One approach is to get two smaller 2.5 gal fuel jugs as they are lighter and you can buy less at once. You can of course buy the bigger jug and fill it less and still have the option to have 5 gallons if needed.
1. Are there any nifty things out there that make mixing gas and oil easier?
Going metric can help for some ratios. Getting a ratio-rite is not a bad thing. Either way making a chart for you ratio will help prevent math errors.
2. For storing your fuel do you have one container that is strictly just for gasoline, and another separate container for oil/gas mixture?
Trying not to store fuel is best. We try never buy and mix more than we are going to use. There is a pump for the spec gas required at the track in our case.
Although we never have fuel issues we are going to step up the care we take in 2014. That includes filtration out of the pump as part of trying to maintain the cleanest possible fuel supply.