We can’t actually answer your first question. That’s a clear NDA violation because it was a work in progress snapshot of the product that does not represent the final package or what you will be playing this weekend. Your third question also relies on information from the first alpha so we can’t touch it. Things have likely changed a lot since the first alpha.
However, your second question looks like fair game to me. Alpha participants would have had very similar experiences to the people you’ve seen play at conventions or during streams. It doesn’t require prior knowledge of the alpha to answer. Nothing specific to the alpha is required so I’ll have a go at this!
Hunter advice: Don’t chase the monster. You’ll never catch up to it. You’ll be moving around the map and playing Rock Climbing Simulator (hint: you can climb walls by holding down the climb button even if there is no more jet pack fuel). Try to track where it’s going and cut it off. Stick together, maybe have a fast moving scout at a high place looking for the monster, and call out its location. Teams of two are ok, but NEVER someone alone! Press Q to put down little markers to point out where the monster is. The monster is much easier to deal with when it’s forced into a bottleneck in the map or when you try to set up a trap for it. Any shot that hits interrupts a feeding, pouncing, or generator attacking action. The monster is also a sitting duck while evolving and is in an unarmored state following an evolution – much easier to take out.
Monster advice: Sneak, sneak, sneak! I think it was shift key to do that. It is far harder for hunters to track a sneaky monster. Also jump early and often. Point your aim upward and jump away. Throw hunters off your tracks by creating false paths. Stop in heavy brush or something secluded and let them pass. Bulk up your armor and then attack. An armored monster is a dangerous monster. Evolution increases attack power, but it also makes you a bigger, more visible, and less armored target until you armor back up. Always look for that hunter that is separated from the pack. Always prioritize taking out the medic. Run away if you lose armor – you can toughen back up again. It’s also possible to hide inside the arena trap/dome!