I would definitely use both the four actions and the four outcomes. I feel like create an advantage and overcome replace both maneuvers and blocks rather nicely.
Though other than that, DFRPG has too much crunch to do much else. Still, it would make quite a few things a lot easier.
Boosts are to be used quickly, they are the lucky incidents that give you the upper hand just for the moment. As a rule of thumb, I think it makes sense to use them at the very last, until the character who created them has his next action. I've most often seen them used on a defense roll against a character acting right after, so that was rarely an issue anyway. Often, the boosts just get passed to someone else, as well, if they are applicable.
As with many things, it comes down to the group. If everyone is ok with a boost lasting a round longer, then there is no harm in keeping it around a while longer. Though as I like to say: what's good for the goose is good for the gander. If the players have prolonged boosts, so can the NPCs.
Ties on an attack roll can be complicated when you combine them with weapon ratings. Technically, a weapon:1 would then be worse than no weapon, because a boost is worth more than +1 damage.
Then again, the DFRPG already has that option built into it, if you know where to look.
Luckily, I do.
Harry and Billy talk about it in the sticky notes on page 200, where attacks are explained.
Keep in mind though, that stunts are built a bit differently in DFRPG. Especially those to attack and defend.
A Dresden Files Accelerated Edition is actually in the making right now. It might take some time, but the beta so far is really enjoyable. It reduces a lot of the complexities of the DFRPG while still allowing for complex and interesting characters and fun games. I'm really looking forward to the finished product.