How does one determine your level? is it per each little skill thing you have mastered? possibly each mastery? I beat the tar out of 10-15 missions, but have difficulty with friends at 32 missions.
The difficulty level at mission terminals is determined by your proficiency with whatever weapon you happen to have equipped when you browse missions. That establishes your individual difficulty level, but the mission terminals consider the collective difficulty level of your entire group. Choosing what weapon you have equipped and who is in your group (including pets) will allow you to have more control over mission difficulty and payout.