Went from 290's to a 1070 and I can safely say I'm just waiting for the next big amd card to drop to switch. I absolutely hate the nvidia control panel.
so for me I was able to get my card stable around 2126mhz. Ive tried to add more voltage but it just destabilizes. Memory on the other hand, if the memory on your card is samsung you should assume you can hit over 9000 easily lol.
I think so but thats my opinion. Id go with whatever card looks better to you. Im just not a huge fan of how much branding evga has put on their card lol and the font/size.
you could test your card with other psu's but that might not solve it. you might just be stuck with coil whine until you either upgrade or rma your card for a different one.