I just went late last year for the first time. I don't know Vdara personally but I would say the location is good - it's a stones throw from the Aria which is where I'd want to stay if I went back. I wouldn't agree that it's "far" unless you are really, really anti-walking.
1. I would say lodging and shopping are the most expensive. I never felt like any of the shows or restaurants were too obscenely priced - even quite reasonable sometimes because they were so damned good. Didn't get to try any of the, you know, elite 5star places though.
2. I saw Zumanity at New York New York. It's basically a Cirque show with crude adult humor/crowd interaction and some nudity. For my group of friends it was pretty good and they still had some impressive stunts. I would have preferred "O" though if I were to see more Cirque. Otherwise it really depends if any of the musical or magical acts appeal to you. That's the bulk of them at least.
3. I initially wanted to try Mon Ami Gabi but it was always crowded as hell. However literally across the street from it is Hexx which at least serves some awesome breakfast and was never very full. I got some great omelettes and got to try their ridiculous chocolate pancakes, banana nut french toast, and cinnaroll waffle. Dunno how lunch or dinner is there.
Also Aria Cafe (omg red velvet pancakes) and the Tropicana's Beach Cafe were both good to us if you happen to be near one and just want some place to sit down and grab a bite. Not really worth going out of your way for them though.
Also inside of Aria (and I think Bellagio has one too) is Jean Phillipe Patisserie which is an awesome dessert shop. Pretty much everything we tried there looked and tasted exceptional. Worth a look at the very least imo.
4. I'd say so. Two things did the most damage to my group - shopping and gambling. The designer shoppes and malls are pretty cool to walk through but are insanely expensive, be warned lol.
One thing you may not know coming in blind but which is pretty useful - basically every single hotel has a regular queue of taxis waiting 24/7. There's no need to hail one or anything like that so long as you're near a hotel. It's either at the main entrance or they may have a dedicated ramp for it but they're basically open to anyone, just stand in line (if there is one) and tell the attendant where you're headed. None of us drove anywhere the entire time, all walking and taxis - which honestly aren't that expensive as long as you aren't taking them to go every single block imo.