You should be okay IMO, Blue Damsels are not friendly ish and depending on what you are going to add later, most aggresive goe in last, just be sure you want him because they are hard to catch with the rock and all.
bob
Look at a neon goby really small, I do not know for sure, but you might want to replace the Damsel with a blue green chromie, same family but less agressive, get other opions on that, I put in 2 high fin gobies in my tank once, a bully wrasse nailed them for lunch as soon as they hit the water, he is history now anyway.
Bob
corals generally don't add a load to a system (or at least, not nearly as much as fish do)-you should be able to add at least a few corals at a time, if you wish
i would always advise adding only one fish at a time to any system, and giving the system a chance to adapt to the change in the load status quo before adding another