If it were me (and it was at one point, I had a Giant OCR3 with a very similar set up) I would change those shifters asap. You are losing so much time monkeying around with those while you are racing. You can't shift them from the drops which I found to be a complete nuisance. Yes that stem weights a lot and since you've been professionally fitted there's no need for it.

I would honestly keep an ear out for another bike someone may be selling. You have a nice bike but it would also be good to have a rain bike. You may be surprised how easy it is to sink $1000 into the bike you have and I'm pretty sure you could pick up a used bike for about that too. Keep it in mind cuz then you have a backup bike which in racing I've found is a good thing to have. Unfortunately wrecks happen and bikes have to go to shops where you may not get them back for a week or so.