hmm, basically, you have two options, that I prefer to combine:
1. get a good coder that can put part of the EA's logic server side (including authentication), part of the logic in a heavily obfuscated DLL, and just the bare necessities in the ex4 file.
2. use MQLLock to obfuscate the code and put most of it in a DLL.
Both work, for my EA's I combine them.
When you fall you learn, then you get up and you try again until you master it.