What else should I consider to make my code completely unnoticeable?
Well timing is one thing, a human being can only click/type/read/decide so fast and to what appears to be random timing.
If it is human behaviour you are seeking to mimic I suggest you randomize timing on certain functions.
Google is a great example of such an effect, ever had to fill in capcha's ?
Too many ,what might be recognized as automated requests, either too frequent or with too short a interval, it is detectable.