Did Booster create Quote and Curly?

Eh...

I agree with #2, he is so gifted with technology (booster 0.8/2.0), maybe he designed some robots (not necessarily Quote or Curly)

I don't think Booster really had a hand in creating any robots.....
Didn't he just come to the Island for research? And the Booster's were made to help exploration; they're a far cry from robotics like Curly or Quote....

 

but they fit robots. :\

 

Humanoid

but they fit robots. :\

They were designed to help Booster explore the Island, if you remember his notes. Quote and Curly are also humanoid in figure, so the Booster's would have been an easy fit, even if they were made for humans.

 

What exactly ARE boosters? are they special shoes? or like a jetpack or something?

 

Jetpacks

What exactly ARE boosters? are they special shoes? or like a jetpack or something?

Pretty sure they're jet packs.
You see them on Quote's back when he uses them, and 2.0 looks exactly like one.

EDIT:
Actually, they both look just like jet packs.

 

You see them on Quote's back when he uses them? I never noticed.
And the first time I played Cave Story, I thought v 0.8 looked like rocket boots, but I can now easily see they are jetpacks.

 

Yeap

You see them on Quote's back when he uses them? I never noticed.
And the first time I played Cave Story, I thought v 0.8 looked like rocket boots, but I can now easily see they are jetpacks.

It's kinda hard to see, but I noticed them when I was making Lowell's sprites, while using Quote as a base...
They're like 1 pixel wide and 3 pixels long across his back XD
{You can only see them when he's actually boosting, btw}

 

You know, I don't know wether the human expedition came to study the mimigas, but if they did - one of the best none-crown explainations, but there's also the more sense-making one:

The island is flying. How is it powered? The humans want to find that out for obvious reasons (vast amounts of areas to live on, cheaper charter travels), and among other researchers, they've got the flying tech expert prof. Booster.

But they could also have comed to study the mimigas and find a way to e.g. make them impossible to frenzify with the red flowers, or perhaps kill them (though they seem too nice to do this... or did they change their view after Itoh and Sue got tranformed?)