Would it even have helped the Wii U last year if games like Bioshock Infinite and Grand Theft Auto V came out on Wii U? I think maybe GTA would've brought up sales but in the long run made people think of it as even more of a last-gen console.

It would have, but it didn't happen, because of the Nintendo stigma.

if 30-40% of software sales were 3rd party on Nintendo systems.........yes.

Yes, obviously

No, the graphics would make the games look like the PS3 or 360 everybody already had. Nintendo messed up by funnelling all of the manufacturing costs into the controller at the expense of hardware power. It's a bit like MS with Kinect but on a much larger (and worse) scale.

It definitely would, to what extent is debatable. Lack of 3rd party games makes the Wii U basically a secondary console in most cases, so the adoption is very slow. People wait until there is a acumulated library of games they specifically want to play, not to end up with a draught like Wii U constantly has, there is nothing granted like in case of PS4/XB1 when you know that you can always find something to play throughout the year.

Yes but not enough! Although that one year advantage would have made a nice difference if the third parties were on board

A little bit, but if only 1 or 2 of the big games came to the Wii U then it wouldn't have made a a difference.

Maybe if those games weren't Call of Duty or Assassin's Creed and they were a delay-less Rayman and a better Sonic.

Big 3rd party games already came to Wii U... nobody bought them.