1. Yes if you get the citi Hilton reserve (going away at the end of the year) or the Am Ex Surpass. Either card will get you instant gold and you can get diamond by only spending $40K in a calendar year on either card (both have an annual fee.

2. Per the T&C only if you are upgraded to the exec floor. Gold's used to get lounge access before they started giving out the status so freely with things like fast track and credit cards. Some US hotels will give all gold's access if they don't have a breakfast benefit but due to the overcrowding at the lounges those hotels are becoming more rare and they are offering other breakfast benefits for Gold's. The only lounge I know of that still give all gold's access are the Boston BackBay and the LAX Hilton (and the LAX Hilton is suppose to either start giving gold's a voucher for the coffee place or give diamonds a full breakfast soon to ease the overcrowding, and I'm hoping it's the later since it's one of the worst lounges in the system).

3. No, the lounges vary greatly. None of the US lounges are worth writing home over and a lot of them no longer have concierges or people to check you in (this is a huge benefit at hotel lounges that have them you just go to the concierge at the lounge if you are a diamond or on the exec floor and avoid the long check in lines). Most overseas lounges have happy hours with comp alcohol. The only US lounge I know of with comped alcohol is the downtown Seattle Hilton and that's just one or two beers and some cheap wine.