I've played GOW since the ps2, started on a demo disk that was the hydra fight.

You can definitely easily play the old games nowadays, mainly because emulators have become so easy to set up.

You can but ill be honest you dont miss out on much. The game still holds up but its pretty different from the original. You can still play it and get deeper lore though. Theres times where kratos will reference something obscure. But not in a pushy inside joke kinda way.

If you do go back play it on normal. My friend made the mistake of going in blind and its got some old school quarter eating moment with enemies. It gets repetitive even due to certain play styles not being as viable. So if you do give it a shot do it casually.