"I want to live well."
Translation:Я хочу жить хорошо.
Usually before or after the virb it corresponds to.
Я хочу хорошо жить/ Я хочу жить хорошо.
It is probably better in this sentence to put it at the end, because that emphasizes it; you obviously want to live, but you're telling the other person how you want to live: well.
Is хорошо more of an adverb, and добрый an adjective? Or can they be used interchangeably?
Хорошо́ 'well' is indeed an adverb. However, the corresponding adjective is хоро́ший (fem. хоро́шая, neut. хоро́шее) 'good'.
До́брый (fem. до́брая, neut. до́брое) can mean 'good' in some contexts, but its usual meaning is 'kind'.