Blusher attachment options

Out of those options I'd do sewn on. If it's on a separate comb, that's twice the likelihood of damaging your hair if/when you take the veil off after the ceremony for the reception, which I'd personally want to avoid. Plus you have to have two good attachment spots that can be easily hid within the hairstyle.

I can't really imagine velcro, which might have some benefits or might, as you say, get caught in your hair so I'd go for sewn as the safest option, honestly.

I also would sew on. You will most likely be removing them both after the ceremony so might as well make it easy on yourself

I am doing a blusher as well and am having it as a different comb so it is secure

I think having the blusher sewn on would be easiest to get in and out of your hair and the most secure option!

I'd just think through if you want any pictures without the blusher or if you're ok with it being permanently attached!!