You are writing a story purely for reader's online engagement? It's not my style, but since you have clearly defined your goal, the only advice I can give is to remember that the masses are generally lazy. Give them minor input and they (may) be alright. But if you overload them with direct choices the majority will flee. Leaving you with a minority of individual readers who are just as likely to be winnowed further every choice you have them make, as inevitably some will be unhappy. After that, you might have a stable few who stick around, until your enthusiasm ultimately dies.
You might be better served with an initial poll asking your readers the type of story they want to read before you begin. Write a story with those guidelines yourself, then pay attention to the comments and use what serves you and your inspiration.
I am of the opinion that appealing to the masses might make you successful, but it will almost never produce quality, if such appeal is the main drive. Whatever happens, have fun exploring creativity in the chaos of that, learn from it, but don't expect a masterpiece. I wish you well.