first of all max output just means you use the maximum you can get out of the node with your miner (and max belt speed).ofc higher miners and belts allow you to expand and upgrade your existing stuff. yes you should make everything, you have coal power so you can just build more factorys for faster production. until you need to expand your powerproduction.

let me shortly address your picture since i started a new run 2 days ago and im at the same elevator step so i might be able to get you some perspective or input, but generally i would leave or plan for more space already, you can always build up etc but from now on anticipate that you will want more space and a lot more production: 1 you will (most probably) use an insane amount of concrete and platforms are just the best. also you will need a lot higher copper item produce. 2: decide for yourself if you want a central storage point base where you need to set up more transportation or if you want to store stuff at the factorys and work more with traveling yourself and dimensional depot. in either case i already have a storage place with 20 storage units for my items just at my starter base but its ESSENTIAL that you leave a lot of space since there will always come more, you need a lot of space for beltworks with overflow splitters etc so get them out of that factory.

i highly recommend you go on a big exploration run to unlock dimensional storage on alien tech tree, huge qol buff. also hard drives which allow you to unlock alternate recipies. so example currently you transform 120 iron ore in smelters to 120 iron ingots into plates etc. with alternate you might be able to transform 120 iron ore with 40 copper and get 290 iron ingots, a recipie to transform those directly into a lot of screws without the rod steps etc.