Saturday Mac riddles 2

Here are this weekend’s riddles to entertain you through shopping, barbecues, and recreation.

1:
I’m Hawaiian in origin, and I hold so much together even though I’m less tangible than Vulcan’s fabrication thrown over Venus and Mars. Now I’m being replaced by something even more invisible. What am I?

2:
I might have been the booking agent for a musical couple, but among my many jobs is protecting your work each hour. Back in Sierra, though, it all got too much after only a couple of weeks. What am I?

3:
What is the smallest number which is two-thirds of 6?

I will post the answers first thing on Monday morning.