Will the RX 570 Nitro+ fit the OS?

Question

Video cards

Hello! I was going to buy a new video card Sapphire AMD Radeon RX 570 NITRO + OS 4 Gb
My system is this:
Intel i3-3330 3gHz (Ivy bridge) s1151
MSI Z77A-G43
(8Gb) 2x4 Gb Kingston DDR3-1333 (667 MHz)
PSU Huntkey 600W APFC- 600 (12+ 18A).
There are 3 questions:
1) will my video card performance be cut off, one can already say, old processor?
2) will my bp pull it to the maximum? (previously there was a gluttonous 1280 Mb 560ti 448 cores 320 bit with additional power supply (6 + 6 pins), the power supply unit pulled the vidyahi at full load)
3) add. power supply on video card 6 + 8 pins, for 8 pins is 6 + 2 pins suitable?)