Yes I am still in act 1. If I'm understanding your post correctly I also think I understand exactly where the other entrances will be but I will not spoil it for someone who has not reached this point by telling you my thoughts on it. One thing worries me though. Upon finding that first key I went directly to the Battlfield and did not drag the Newly found key into my inventory as seems to be the best case scenario so that I can use them in the other acts. Is this key lost to me forever or will i simply be able to collect the key once I exit the battlefield?