Let me preface this and all future comments on the matter: I'm no expert, so I offer no warranty as to the accuracy of my adivce. Everything I know is all self-taught so I'm sure others that do this for a living can offer much better advice.
I don't know what the maximum threshold is for fuel adjustments but the whole point of fuel trims is to keep your car safe so as long as stays under that threshold you shold be safe but it's definitely not optimal.
I don't know how to pull the datalog off the tuner to upload it but I'm sure it can be done. Problem is that they use a propritary format so you can't open it in excel so only someone from diablo can view it..