I had a LBS look over & tune up the bike back when I resurrected it from the basement this summer to start commuting. At that time they said that the front shifter wouldn't go to the big chain ring, that the internals "were shot cuz there's a lot of plastic in there that just wears out" and that it would be more cost effective to just replace the shifter. I live in a hilly area (thus the screen name!) and frankly for the first month or so I had no need for the big chain ring. So I let it go until now.
Now I've improved enough that I can actually get some use out of those bigger gears.
I've read that the higher end Shimano components use bearings instead of plastic bushings, etc and this makes a real difference in lifespan. I plan to put this commuter to use for some touring in the future and I just don't want to bother with mostly plastic internals when I have a choice. Admittedly, I don't know how high in the Shimano hierarchy I have to go to get beyond disposable components. That's why I used the "XTR" term, but I am not informed enough to really know for sure.
I didn't realize I could separate the brake levers from the shifters; good to know. That might save me some money up front. I can see how a Deore brake lever would be close to XTR-level durability since it is such a simple device, as opposed to a shifter.
>"5) Not sure what that means"
It means "what/who are your favorite sellers for buying Shimano components?". Google searches yield thousands of hits so I'm looking for guidance on where to buy the hardware.