I am sort of glad that I learned handloading before the internet.
OP: you should be fine. OAL is not critical with revolvers. You want about three quarters of the bullet shank inside the case. Then just set the crimp die to remove the flare. That will almost certainly be adequate. If you find that the bullets seem a bit loose in the case (try forcing them further into the case by giving them a bit of a push against the loading bunch or something) report back and folks will give you good solutions. You probably won't need to worry about it, though.
My experience with plated bullets has been fine. They are clean to handle and shoot, and easy to work with. I generally prefer cast, but plated often gets the nod for indoor work, as the air handling system at one of our local ranges doesn't do the job. For that place, I'm happy to spend a little extra for plated.
HP38 is a clean burning powder which doesn't need a lot of energy to light. I have extensive experience with a load similar to the OP's and never have had an issue with unburned powder or soot. Shoot enough without cleaning and you'll start to get a bit of copper wash on the outside of the gun (it takes about 700 rounds, in my experience) but even that wipes right off.
Short version - the OP's load is perfectly safe and sensible. He is to be commended for his cautious approach, and hopefully not buried under an avalanche of minutiae.