Hmm.. I think Quote could be named as such because he's a copy, a piece, or a "quote" of the original. Quote seems to have no recollection of his past by how he interacts with others... Meaning as you learn things about the game, Quote takes this forgotten knowledge to be fact to piece together who he is. Only by the player's positive decisions towards the Best Ending does Quote perhaps start to remember the past, the way he reacts to certain situations and the mysterious Jenka history could be interpeted as one of Quote's lost memories surfacing.
Just a random idea lol
Anyways as for free will, AI seems to be very advanced in Cave Story. Whether it's MALCO or the wandering robots or Curly and Quote... They act very human in their responses. I don't believe any of the robots were blind in their ability to think. Are there safety protocols that force them to do certain things? There is no evidence either way in Cave Story...
How could AI and robots be so advanced and yet you have an old fashioned helicopter transporting scientists? Well, you could say magic... or magic influenced technology... or perhaps just like the long lost kingdom of Ballos, there were people of high technology that have long since been lost to time. [You do see strange things in Cave Story, like an organic Core inside an ancient technological base deep in the bowels of the island of Cave Story...] Don't tell me Jenka and the Gaudi's built that base
And, it seems unlikely that the military forces of the island would have had a secret base on the island or built that base on the island....... The Gaudis conversations imply that Jenka created the Labyrinth, and put the Gaudis down there to protect the heart of the island... So that base was probably there already... The fact that the whole water system seems connected to that base but was regulated or controlled by the core seems like it could be further proof that the base and core have been there for a long time. It's hard to say though...
*cough* and as for Quote and Curly's relationship lol
I think they aren't originally designed by the same creator. So they aren't literally robot brother and sister in my opinion. I don't sense that kind of relationship from them... maybe. I'm basing this upon their minds, rather than their bodies. Unlike humans at this point... robot bodies can be replaced, and their minds can be transferred to a new body. So, probably, originally they weren't the same robots they are now. But, that their current bodies and technology could be created by the same scientists/country/manufacturer.
This of course would make it tough to define who they are... Let's say Curly and Quote have had different bodies over time [even if they look the same], but the same minds basically throughout. However... they lose their memories in Cave Story.
But facts are...
Quote and Curly were sent together on a different mission than all the other robots. Even if they lost, or something happened, and they forgot their memories, even if their bodies might have been damaged as well...
Ten years later, Quote and Curly find themselves drawn together again. Quote didn't have to save Curly or spare her; Curly didn't have to save Quote. [taking Best ending as canon] She didn't have to give Quote this "Iron Bond"... But, they did meet again, and did give Quote this seemingly valuable strange object she had been carrying. It does not seem to have any other importance except that it is significant to the two of them.
And finally, how does the best ending end? Q&C accomplish their mission and... randomly go somewhere they can be free together. Not back to base, not returning for another mission or to be fixed up. Not to look for other robots... It's simply let's go somewhere where we can live the rest of our days peacefully (with a great view). Now what kind of robot response is that. I think the history between Curly and Quote is long and maybe they decided to protect each other once upon a time...
Even if Quote and Curly are different than when they first started ...
"Iron Bond - Your tie to Curly Brace, the only warrior you would trust your back to. Surely you will meet again one day..."
This is the closest thing to Quote's own words or thoughts directly given to us. The only warrior Quote would trust his back to. That should sum up Quote's relationship towards Curly. Someone that he would risk his neck for.
I think Curly's relationship towards Quote could be much more complex. Assuming she got her memories back, whereas Quote did not... She might remember something that causes such a decision.
Balrog : So what are you going to do now? I can take you anywhere you like.
Curly : Hmm, you're right...
[I wonder what she was thinking, since she did not consider this wild decision until Balrog brought it up. Was she wondering what happens now? Do we go back? What's left for us?]
Curly : Our mission is over, and now I just want to live out my days somewhere where I can relax and enjoy a beautiful view...
That sounds frivilous doesn't it? But, then again maybe this line speaks loads about Curly. Not that she's frivilous
But, that this is the exact opposite of what you imagine a robot doing. What's her purpose? No she isn't thinking like that, she's just wanting to live out her days in peace.
What about when she saves Quote and you wake her up [drain the water]... You're alive! Oh, I'm so glad... I didn't think we were going to make it. Once you fell unconscious, I couldn't think of any other way... (to save you) Looks like my air tank worked just like I'd hoped. Ah...
I added that (to save you) because I think that's her type of thinking. Simple, not stupid; but simple. She couldn't think of a way to save both herself and Quote, so she saves Quote at all cost.
When you first meet Curly, she doesn't give you a chance to explain, she simply begins to attack because... she has it in her head you'll kill them! Because she recognizes you as a robot!
She's not very robot-like, and that's why I call her a broken robot...
She seems short-sighted and rushes into situations... Not very logical.
She quickly seems to care for everyone (even enemies), but maybe specially Quote.
Just because she regains her memories thanks to the magic talking mushroom (!?), doesn't mean she regains who she was before she lost them.
So, um... I think Curly's relationship towards Quote is simple caring, but also something deeper thanks to their prior history together.
Brother and sister relationship? Meh...
Romantic relationship? Eh,...
Maybe a caring broken robot with a promise and a robot that is missing who he was.
But, maybe it's best that way?
So if you had to label it, I'd say brother/sister relationship... but that's only on the outside. Maybe it's more like, once was similar to intimate (as far as robots go?), but now it's more like lovingly looking after the one that used to know you, so now you start over with a new beginning...?
[oh and as for laws of the universe, and level of technology or what kind of technology, science and how it works, blah blah lol well I simply will say, not enough information. It's basically comparing fantasy to reality. Although feel free to say how IF this was our reality, this...]
Hopefully there was some sense in my writing
I sleep now