No need to start this debate in this person's thread. Make your own thread, don't hijack.
As for OP, yes, it will leave welts. I bruise on my knees from wraps, hips, thighs, and shoulders from a suit, and tris and chest from a shirt. Part of learning gear is learning how to not panic from the discomfort.
When I first put on equipment, I spent a lot more time in it before a meet than I do now. It takes a bit of learning to figure out how to use it right, but now that I know my suits and shirts and how things need to be, I put on equipment maybe once a week the last six weeks before a meet - and that's if I've planned well and the meet doesn't sneak up on me.
As for when you're ready to put on a shirt - that's a respectable raw bench. I think if you want to compete equipped, you might as well try it out. Are you still gaining weight? If so, see if there is anyone around you with an old shirt for you to try out. It stinks to invest in a shirt and then grow out of it immediately.