Just return it in that case. You seem to have came in believing you were going to hate it
I don't see why you asked your Girlfriend to spend $500 on a system you seem to have been set on "It's undesirable, I'll wait for exclusives." You seemed pretty happy with your PS4 and PC, why have that money be wasted? Should of held off until they got exclusives you wanted.
Anyways, if you plan to keeping this things, some advice.
Calibrate your Kinect, and put your TV volume higher than normal when calibrating. Voice Commands work perfectly for me when it's calibrated. Also, you aren't supposed to fucking yell at the thing haha. That makes it even more inaccurate. You're messing up there.
The "hand waving shit" isn't working because this isn't the Xbox 360. You aren't supposed to wave your hand for Kinect to detect you, that actually makes Kinect NOT detect your hand. Just hold it up there and leave it in mid-air for a while, than your hand will work.
It boots up slowly upon Cold-boot, yes. But who cares, you aren't supposed to turn the system off. Select it to be on "Insta-On", so it's always in Stand-by. As a PC gamer, you most likely don't turn your PC off, so you should be used to this. Boots up in like 5 seconds with Insta-On.
The Sticks, Bumpers, and Triggers is your opinion and I won't argue it, but are you sure you're using the controller right? You're supposed to roll your finger off the Trigger and into the Bumper, and it works lovely. I love the Sticks/Bumpers/Triggers and think they're the best I've ever used, but that's just me.
Also, make sure to study up with the voice commands, so you make sure the Kinect works like it's suppose to, and it isn't user failure on your part for not using the proper commands.
Also, remorse for something you didn't buy?