Similar experiences? Absolutely. In my first homebrew campaign that I ran, it all began to go wrong when during the second session I handed several important quest papers to my group's LN wizard (a first time player) who had assumed the role of leader. She glanzed at the documents as others looked on in silence, and without saying a word simply folded them and placed them into her bag and never shared their contents with anyone: she rather changed the subject as if nothing had happened (At that moment I realized I should've made a copy). Things escalated slowly from this point onward and the party in question managed burn down (or indirectly caused the burning of) five villages and settlements, narrowly escaped authorities twice, three times skipped the quest givers because they found them to be suspicious and tried to start religious holy war against all civilization several times before I finally ended the whole mess.
I'd like to stress that I had both CE and CN characters running with the group who played their parts admirably: they followed the quest-hooks and killed only in order to get more loot and booze. It was the Lawful neutral players that did all the burning, derailing and destruction.
While I do understand that your brother's behaviour has left a rather nasty mark on the story you've created, maybe you could try to experience the game through his eyes. Not all players are interested in advancing epic plots centered around fates of kings and kingdoms, some are there simply to have fun while killing monsters and looting dungeons. I've noticed that when players interests conflict with yours, that's where the frustration and derailing begins. My players never wanted to be involved in a plot full of politics, intrigue, and spying that at first I tried to force upon them. They'd rather simply go on a pirate adventure and kill anything that happened to come by. It's an arduous job to combine the two, gameplay and story, but I see it as entirely possible.
Looking at the other side of the coin, my gang of murdering arsonist left me with some great homebrewn lore: in my campaigns, it is now established that halflings settle their differences through events called "games", where the only way to win the said "game" is to prove that the other side cheated, other goals be damned.