The best thing to do is always QT. Get a heater in a bucket for the LR
. Not just for the possible ammonia spike, but to make sure there weren't any baddies hitching a ride that would mess up your setup.
As for coral, if you have room for it you can put it in. Once a tank is cycled you can throw in as much as you want as long as you can supply it the needed nurishment, usually strong enough lighting and flow.
It is ok for now if you aren't using reef crystals. It really is only an addition of calcium, but if you dont have a large stock of corals requiring calcium then you will be fine. There is no need to ever use additives if you do weekly water changes. And if you want, when you need to get more salt pick up reef crystals.