The biggest issue with starting an RP off slowly is that few players ever manage to stay with the RP for more than a few weeks. If we start off at the very lowest level possible and very slowly accelerate as the RP goes on, I fear that you may lose all your players long before the plot can begin proper. I've experienced it quite a number of times before-- there are a lot of RPs opening up every day, people have very limited amounts of time and interest to invest in any one of them, and if an RP is proving to be unsatisfactory, they're fully capable of simply pulling out and finding another one--, and it results in the painful death of many RPs that tried this thing before.

I do recognize the fact that these are low-level servants, but I'm not sure I see the point of placing the player characters at just above human levels in a setting that starts with "has immense control over one aspect of nature" and ends with "controls literally everything related to a very broad domain of reality". That is a very dangerous recipe for powerwanking from everyone [i]but[/i] the main characters.