And rules give you a list of what definitely can be done. They give you a tool kit. They also give you an idea, sometimes, of what can't be done; they provide more of that situation to resolve without the GM having to say "and no, you can't spontaneously add specialized gear to the princess's possessions." Or other such things. They help you know what is within the realm of possibility, and also help you answer questions of "can this creative solution even work?" They also can help you come up with creative solutions. You look at your box of tools, and see "oh, she has extremely long hair that can support her own weight? That could be useful!" whereas you may not have even thought of the Rapunzel solution without the reminder.
Nonsense. You apply it yourself later on when you say the GM will call the convenient perfect-for-the-situation sword "silly." That solution is not "good enough to accept." But why? Because it's "silly," of course. But...what makes it "silly?" Sure, I am pretty sure that most people in this thread agree with that assessment (I certainly do), but by what objective standards?
Everything in a free-form game is basically trying to find "a solution good enough to accept." Because there is no objective standard. In a rules-lite game, the objective standards are fuzzy, so the question is whether the solution is close enough to within the rules to accept it. More rules-heavy games have much brighter lines of what is "a solution good enough to accept" or not. If the d20 system Princess does in fact have that +5 dragonbane sword of fire immunity on her list of equipment, well, she has it. It stopped being "silly," since clearly she planned for such an occasion and it wasn't pulled out of a dark southerly location once the situation was known. (Or, if it was, it was done according to other rules; perhaps Her Highness has a rule that empowers her to be a brilliant planner by letting her claim to have prepared for just such an occasion so many times per day.)
Sure, but that's just as likely in a rules lite game; in fact, they invite it more because there's more room to wiggle "but it SAAAAYYYYYS..."
As noted above, this is where the GM is saying "no, that solution isn't good enough for me to accept."
Absolutely.