More amazing sometimes I wonder how some users can even uninstalled system stuffs from an unrooted phone. Seen this occurrence few times in various threads !!
Easiest n fastest ( no headache) is using Odin in PC n flash Chainfire CF Root - get this from XDA Note4 thread original android development. It takes only few seconds to root. No data will be deleted during rooting n is very very very safe process. Don't allow those pessimists discourage you about rooting. Only a dumb guy can brick his phone rooting. Just follow the instructions. Is so freaking simple even my neighbour primary 6 son can root his father phone. Make sure you download correct cf file matching to your model
Closest custom rom to stock is Wanam. I would recommend Sweet Rom v14. Rom you need to try yourself to assess n there is no best rom. What is best for me is not necessary true for you.