If I have Deathstroke and my opponent has wolverine and we are both on the same piece of hindering terrain(i am adjacent but diagonal to him)

Can I

1. Use his outwit ability on stealth to make it so another character can attack him?

2. Use an attack on wolverine(making him lose stealth after the clicks)

THANK YOU!

No. Outwit always requires a line of fire regardless of adjacency. The same is true for Perplex and Probability Control.
Yes. The two figures are adjacent so you could attempt to hit him with a close combat attack, but not a ranged combat attack.

Kid Zemo

Another thing....

Is the top of those trucks on the outdoor level(the one that comes in the DC starter) considered Hindering terrain/clear terrain/ or blocking terrain?

Hindering terrain has (typically) thin lines that follow the outline of the thing itself. Blocking terrain has (typically) thick black lines that follow the outline of the SQUARES the thing is in.

As such, the trucks are hindering terrain, not blocking.