Custom character script

So as the title says I want to make a script full of custom characters I want to make( a lotr script with the main point being the one ring) but because these will be the first time I make custom characters I have some questions

1.where can you make custom characters I know about bloodstar but is this the best site?

2.where can you make the icons for them?

3.how should the characters be balanced, if I make a very strong character compared to the base game but the rest of the charcters(including evil) are at around the same strength us the character strong or weak?

4.how do you usually come up with ideas to finish a full script?

Thank you in advance even if you can't completely answer my questions