Need advice on this gaming PC build please

http://pcpartpicker.com/p/cxvcvK this is mostly what you wanted with some tweaks for better game play, if you need it cheaper we can do something about it but you can click that link and even built it your self and it will tell you if its compatable or not, and this build is.

That's a pretty solid budget build. A few things I would mention-- The G3258 only supports DDR3 1333. Check to see if that's any cheaper if you use that processor. ( I didn't see any at that site.) If not, the CPU can run the RAM at the lower speed. Next, the Corsair CX series has a bad reputation for unreliability. I would try to upgrade that a little. From that site, I like the Antec NeoEco and the High Current Gamer models(Though I don't think the NeoEco comes with a power cord.) I'm not really familiar with the cooler, so I'm not sure why you chose it. The Cooler Master Hyper 212 EVO is kind of the cheap standby and Noctua's are popular for those spending more money. Check reviews for that decision. The hard drive you have will work, but the 3.5 inch 1TB Caviar Blue should be just about as good and is about $40 cheaper. My last suggestion is to drop down to a 2GB 960. There are times where the extra two GB will make a difference, but it's not worth $100. Most of the time the bottleneck will be the processing power of the 960. Sometimes it will be the processing power of the G3258, and very occasionally it will be the VRAM. It might also be worth checking prices on the R9 380 and 380X. Both are a bit more powerful than the 960 (especially the 380X) and I would go with one of those if the prices are within $15 or so.

1. They look compatible. You might put them into pcpartpicker to get an automated check.
2. This is tricky. The 960 (or 380) should be good for a year or two, but it depends on where game studios go with development. The Pentium is the biggest issue. It's great with single threaded games, but it struggles a bit with multithreaded games or multitasking. Games have begun to list higher core counts as a requirement and for a while, Dragon Age: Inquisition wouldn't even boot without detecting at least 4 threads. So that could cause problems within the year.
3. Probably, I'm not really an expert on coolers or overclocking. Check reviews comparing the one you chose with the favorites, like the Cooler Master Hyper 212 EVO. But overall, the case should be fine. The rest of the parts don't put out that much heat and even the G3258 is a low power part.
4. Yes-- the as I said , the CX is not the most reliable. But a good PSU over 500 W should be sufficient.
5. See above.