Fair play for taking the challenge on that was set by the forum, realising that it wasn't as good as expected and coming back for more!
It seems to me that the combination of your tuner talking b*llocks and your own pride has gone against you, but it appears you've done OK! I'd personally have to think twice about coming on here and get flamed like you have and still come back! But everyone here is a good laugh so it's all good!
I genuinely hope you get a good result from this car, but I don't think anyone is expecting anything spectacular! Maybe going single turbo is the answer?
From my experience with this forum, lots of people come on with a few misguided views and are put in the right direction (if not forced in the right direction) with the help of some very experienced Supra owners, and they certainly know their sh*t!
Fair play and welcome to the forum!