Can You Get A Brazilian Butt Lift As Many Times As You Need In Order to Reach Your Desired Look?

You certainly can have re-augmentation with fat to the buttocks provided that you have additional areas to harvest from.

Yes, the Brazilian Butt Lift procedure can be repeated as many times as you need to obtain the results you desire. However, you obviously do need to have enough fat remaining after the first procedure to do it a second time.  I have had a few patients undergo the procedure more than once.  The vast majority however, are significantly larger after just one procedure and are Very happy with this.    I have never seen any patient of mine who was unhappy with their results or who lost any significant volume of their fat.

You are also right that too much fat at once isn't good.  But the big question is "how much is too much?"  The answer to that question is partly dependant on the technique used by the surgeon.  The most important thing with this procedure is to find a surgeon with great "Long Term" results.  That means seeing lots of results at least 3 months after surgery and preferably 6 mo or a year after surgery.  If the fat is there at one year, it'll probably be there forever. 
Don't just get it done!  Get it done well!