Omg, monkey please stop.
Your wastegate is working fine from what I have read, the problem you are having is the ported wastegate on top of a 6 port motor. Stock I'd say you are right on the money boost wise, but you may experience a fall off on peak boost higher in the rev range close to redline.... maybe, I am not certain on that though.
It comes down to this, that wastegate is venting to much exhaust, and with no controller, there is no way to stop it. Invest in a good boost controller (you can re-use them on multiple turbo / car setups.)
It'll keep the wastegate shut until it senses max boost, then slowly actuate to maintain the desired boost pressure, something you can't do with the stock turbo setup. Since it is ported, then you shouldn't experience any boost spike, but without a controller, you'll see less boost than you want.
I have two turbo's sitting outside. S4 and S5 if you want pics of the wastegates and the actuators. They either work or they don't 99 percent of the time.
Get yourself a controller, get boosting, and enjoy.
-Maniac