I was waiting for this...

Honestly, I have never had this problem before of all MTs I've had. I'm not going to say I'm pro or anything, the criticism is definitely warranted.

Do you think the helper spring could be working against me?

I'm sure you saw the thread I'm referencing but:
http://www.the370z.com/engine-drivet...er-spring.html

What kind of tips can you give on some better shifting?

First manual car? Maybe its your first import manual car as domestic clutches are much stiffer. I'd bother Nissan since you need a new clutch at 5K, can't hurt to try although you might get stuck with the diagnostic costs if they don't cover it. Then again if you are friends with the Nissan tech maybe it'll be free for that as well. Try not to have your clutch engaged for more than 15 seconds. Other than that, consider this a learning experience.

I've always had manual cars (until now) and never burned a clutch. I've driven all to 100k miles on the same clutch. Have dealer check might be something else (can't imagine what though)