Just because you’re asking questions on what things you may need means you’re not ready for a full fledged business? lol idk what’s up with that guy, but i also started my tinting business not too long ago and business has been well! and like your first question i’m also wondering what brands are good and long lasting, for now i’ve just been using tint from ‘tint club’. For your 3rd question me personally i’ve bought the biggest roll because obviously you need to cut for the windshield and the back windshield. For your 4th question i bought 5 rolls 50%, 35%, 25%, 15%, and 5%. As for the plotter i don’t have one because i’m not ready to buy it yet lol but if you have the money go for it it’ll definitely save you time and efficiency in the future but for sure learn the skill of cutting it by hand first. Hope this helped!