I don't find the whole "if the leader dies we ALL die" thing annoying because I got used to it through the Persona games. It gives you that kick to really think on your feet, and also gives you a stronger connection to the current character that is your leader; and through that it gives everyone a chance to shine as the 'main' character in battle for a little while.

I've suffered some shameful defeats while getting to grips with the battle system, some at the hands of bog standard enemies wandering about the place. The most shameful being the battles where (SPOILER)you intrude on two other enemies fighting one another. I didn't quite figure out to kill one from one side, then one from the other, and instead just killed one entire side at a time. Poor Vanille died so many times until it clicked I was doing it wrong.

Surprisingly I didn't die once during the Bulbasaur battle. Though it did take a very long time.