If I could pose some more questions (I know there's alot here, so don't feel like you have to answer them all):
When you say 3/8" (-6), what is the (-6)?
Hoses and fittings are measured in sixteenths of an inch, so a -6 hose is 6/16" or 3/8" which is a -6.
Does the, say, $3.50 per foot include the fittings on each end?
No, fittings are extra and price varies depending on male, female, JIC, flat face o-ring, etc.
If it is not too complicated, what does the 100R2 stand for? (I'm guessing that the "R" has to do with the half bend radius rating).
The SAE 100R # is a standard used in the hose industry to rate the hose for pressure, how tight it will bend(bend radius), etc.
Not sure what half-bend radius is.
If you look at a U, the bend in the bottom part is the bend radius, like the radius in a circle. Half bend radius means the hose will bend half a circle of what the other hose will.
You mention that there is some anti-corrosive on the fittings. I guess I was thinking that some fittings might be made of differing metals - which have differing degrees of quality for anti-corrosiveness and I wondered what metal I would want my fittings to be.
They're all pretty much the same metals, it's the coating that makes it anti-corrosive. Cheaper fittings have less or none.
Are all hoses made of the same material? (are neoprene, stnthetic rubber and nittrile all synonyms)?
No, they're not synonyms. Most of your standard off the shelf 2 wire hoses are all a nitrile inner liner which is plenty tough for what any of us here need.
Don't feel bad about asking a question. The only dumb question is one not asked. When you go to a hose/hyd shop, ask for a catalog. There is a ton of info in there. I still learn from the Weatherhead catalog. You can also look here.
Eaton Product Literature Library > Fluid Conveyance > Weatherhead This is the catalog I get all my info from.
Happy reading, Andy.