What is the difference between "Balance" and "Trade-off" ? For instance at these two sentences:
Legal balance between rights and interests
And
Trade-offs between rights and interests
Not exactly, but without further context it's impossible to say definitively.
Strictly speaking, a trade-off involves actually exchanging one thing to gain another. It's used metaphorically, too, and usually in the guise of a "win-win" for both parties.
In this context, a legal balance probably means that the courts will ensure that interests never outweigh legal rights.
In 'balance', there would be a balance between the rights and interests.
In 'trade-off', may get whats asked for, but importantly, also had to give something up, make concession, make a compromise in order to get an agreement.