Most people running 4AGZEs are still using the T50 gearbox. Operating it with mechanical sympathy will prolong its' life, however you should consider that it is having more torque fed through it then it was ever designed to handle.
Failure is inevitable, but treat it nice and you should get a good life from it. You'll know when its' on the way out. Shifts will get crunchier (especially 2nd to 3rd and 3rd to 2nd) and whines will get louder. 2nd gear is usually the one which goes. When this starts, i recommend you start obtaining the parts for a W5x gearbox conversion, especially if you are considering upgrading to a 4AGTE.
Also please use punctuation in your posts, there isn't a single full stop in there.