Yep, you won't be able to use the i7-7700K with that particular motherboard. That board predates Haswell (Socket LGA 1150), let alone Skylake/Kaby Lake (Socket LGA 1151), so it's not compatible.
It'll take the i7-3770K, which at stock (3.5GHz base/3.7GHz Turbo with all 4 cores/3.9GHz max Turbo with 1 core) isn't too far behind the i7-7700K stock (4.2GHz base/4.4GHz Turbo with all 4 cores/4.5GHz max Turbo with 1 core). And since it's a Z77 board, you should be able to overclock it to equal the...
Nope that is a full platform upgrade. CPU, RAM and motherboard. Your old stuff is useless for that CPU. As stated it is the wrong socket. You need a LGA 1151 motherboard with DDR4 ram.
Yep, you won't be able to use the i7-7700K with that particular motherboard. That board predates Haswell (Socket LGA 1150), let alone Skylake/Kaby Lake (Socket LGA 1151), so it's not compatible.
It'll take the i7-3770K, which at stock (3.5GHz base/3.7GHz Turbo with all 4 cores/3.9GHz max Turbo with 1 core) isn't too far behind the i7-7700K stock (4.2GHz base/4.4GHz Turbo with all 4 cores/4.5GHz max Turbo with 1 core). And since it's a Z77 board, you should be able to overclock it to equal the i7-7700K.