you’ll be fine with that CPU, not running pcie4.0 will hurth the GPU a little but the CPU will be mostly fine.

it will be between 75-150w for idle-light tasks, with full power being considerably more but adjustable to whatever you want.

amd chips tend to consume less power.

do you even need to, older CPUs are still surprisingly competitive, the 10700k will remain usable for a long time. all depends what you’re using it for but for things like gaming at 4k the CPU doesn’t really impact performance in a meaningful way, save you money