Aspen, there are answers to both sides of most anything you can want to look for in this hobby. You need to do what makes sense to you. For instance I don't QT my fish either, never have and I've been in reefing for a long time. I took a 10 year break and just got back in about a year ago.
I also don't worry about matching salinity when I get new fish. I do the old tried and true acclimation method that Live Aquaria suggests. It is to open the bag after temp acclimation for 15 minutes, then put 1/2 cup of tank water in the bag every 4 minutes until the bag is full. Then dump out half of the water in the bag and repeat every 4 minutes until full again, then put the fish in your QT or DT whichever you prefer. I add to this a cap full of Prime or Amquel as soon as I open the bag to help combat the ammonia that becomes toxic in the bag once oxygen is added to it upon opening the bag. It doesn't matter to me what the starting SG is in the bag. I've done it this way for many many fish and never lost one to acclimation process. If LA suggests this as their preferred method and they warranty their fish for 14 days, then I say do that.
I also don't believe that ich can be transferred to your tank on any of your cuc members or from corals. I do temp acclimate all of them for 15 minutes by floating the bag then I dump them in. With corals I do a dip in Revive and in Coral RX. With the fish I also do a Formalin dip which will kill most any parasite that the fish could have. I do this dip for 10 minutes.
So you see it can be successful in more ways than one, but it's your decision to do what you think is best for your tank and your critters!