Ok, I guess when you have seniority 1 you will be around 10500USD on an average month.
QR pays the absolute industry standard, nothing more nothing less. No profit sharing, pension plan, bonusses,......WYSIWYG! Same as EY, less as EK.
The problem, as you said, are the months where you are on leave as you loose all the flight pay. You will fall back on basic salary plus few allowances.
The trick is to spread your leave, and to make sure you actually do fly a lot before and after leave. Remember, salaries are calculated from the 10th till the 9th on a monthly bases.