This is just a guess, but perhaps Robin Hood isn’t stealing magic in its purest form (like in the form of energy or pixie dust); rather, I think Robin Hood could try and steal the gold which Rumple spun from straw. We’ve seen Mr. Gold use that very gold in his potions in his basement in SB when he was trying to break the boundary spell.
That’s a pretty good guess given the myth of Robin Hood.
I had assumed that the Infinite Forest was a separate from the EF, because Regina sent her magic through her mirror to thwart Prince Charming from finding Snow White, and she banished Hansel and Gretel there. Also, Rumplestiltskin said in 1×22 that no one could escape the EF without magic, and then he sent Prince Charming to Maleficent’s castle, located in the Infinite Forest. This makes me think that Maleficent used her magic to create the Infinite Forest as a sort of protection barrier outside of her castle.
Hmm. I hadn’t thought of it that way. So everyone lives in the EF but then a neighboring forest is the Infinite Forest. So do they merge at any point? Because if Maleficant lives in the IF and not the EF then Regina had to specifically pull her over (which I guess is true since Rumple said “I knew you couldn’t resist bringing her over” in A Land Without Magic) and the IF was left unaffected by the Curse?