One thing I didn't put in so as an after thought here it is. When I do pin through a part after I pull the pin out I always put a drop of thin CA on where the pin went through, just being cautious, but have been pinning since I was a kid. Yes it is a judgement call as to whether to do this and very small or skinny parts it is sometimes better to cross over them to hold them down. You will over time learn which ones can be pinned and which ones you don't want to.