I wouldn't think that if the white powder is on the lead bullet that there would be a problem. For safety's sake, you might just want to dispose of them. I'd use an impact puller to take them apart.
I sold one of my 550's to upgrate to a 650. Have a few "learning" problems. Hope they go away as I get more familiar with the 650. The 550's work great
I have been having good luck with Winchester primers, no misfires. I have always used CCI in past without ignition issues so was leery of switching to Winchester. With shortages nowdays sometimes you have to shoot what you can find
I have been keeping my Commanders with Woolf springs in factory weights. Seems to be working. On my non carry gun, I use a recoil buffer to help with pounding
Starting to shoot with what you already have is a good way to see if you like the sport. You can always add equipment later on. Start shooting and enjoy