Mace clearly wins scenario two. That's spite so lets only dicuss scenario 1.
Here's the breakdown.
Does blasters beams move faster than Spidey, like light speed or faster?
If so then Mace can win by simply dodging Spidey's first limb attack and countering with a lightsaber attack. Or mace could just block Spidey's limb attack with the lightsaber (cutting Spidey's limb off). Spidey has a chance to win via the webbing though. This is the key for him. He can shoot it in a very wide spread at super speed. This would slow Mace down a little (since he has to use time to cut through it) giving Spidey the opportunity to land a good blow. The Spider sense should guide him in this effort. All in all I say split here or Mace a slight majority.
If the blasters don't move as fast as Spidey (under light speed) then Spidey wins a slight majority due to being faster than Mace and will use that speed to one or two shot kill him (maybe after countering Mace's first attack).
At first looking at the video I though Mace easily wins both. But with some of you guys arguments I say it can go either way depending on who counters first and how fast these guys really are.