Hey guys, I ended up picking this up at the weekend hehe

Got a few questions that some might be able to help with.
I am finding the predator a lot harder to use than it should be. What fire button does everyone have for the predator bound to?
at the moment I have it left as default, I cannot use mouse 3 to fire as that is my mouse wheel, so I end up zooming all the time. Using the "ALT" key isn't bad but is still a little awkward when fights get intense.
I take it the spear should only be used for close to mid range as I tried using it on top of roofs but it moves through the air so slow, the enemy has already gone and it dips too.
Even with the disc I have had times with my x-hair on the target and fired the disc but it has completely missed the target, even when they are not moving

So annoying but I am wondering if this is down to lag or not.
When it comes to using the Alien, what does it mean when the x-hair on the screen turns black or when it turns a brighter white, I know this usualy means you can jump to the wall the x-hair is on but is there a difference between it going a darker black or a brighter white?
Does using focus mode with the alien give any advantage in fights? Does it have a purpose in multiplayer?
Finally can someone explain how the hand to hand combat works: For example,
I the enemy is performing a heavy attack but I unleash a light attack first does that interrupt their heavy attack?
Can only light attacks be blocked or do heavy attacks get blocked/reduce the damage taken.