A:AnswerThis board is a LGA 1151. That heat sink is for an LGA1200. With that being said the answer is Yes. I went through that just so you understood that the 1200 is compatible with the majority of 115X coolers.
A:AnswerYes it supports both. The purpose of having a “Z” series motherboard (Z390) is so that the processor can be overclocked (get more power than normal from the processor) the “k” in the 9700k cpu signifies that it is unlocked and able to be overclocked.
A:AnswerAbsolutely. Just match a processor that is compatible. Use pc part picker or choose the best 8th or 9th gen intel processor that best suits you: