It's not a strict yes or no. 'Said' is a common and simple way to attribute dialogue, but if you use it too often, it might make your writing feel plain. You could try using more descriptive words鍋跺皵, but don't go overboard and make it sound forced.
Well, using 'said' can be okay, but it's good to mix it up with other words like 'exclaimed', 'whispered', or 'muttered' to add variety and make the dialogue more engaging. Also, overusing 'said' can make the writing seem repetitive.
It depends. Sometimes using 'said' is fine, especially when it's clear who's speaking and doesn't draw too much attention.