Scrubbing tugs and tears at the skin and causes friction, so even though it may seem scary to use a glycolic acid mask, it is in fact easier on the skin. The trick is to use it according to skin type. For sensitive skin you can leave it on for fewer minutes than the instructions call for. Or you could try an enzyme or lactic acid which, in general, is gentler on the skin than a most glycolics. Either way, a once a week exfoliating mask is plenty for all but the most congested skin.
For sensitive skin I adore Phytomer's Peeling Vegetal enzyme exfoliating mask. It is creamy and mild and smells divine. It contains healing and moisturizing seaweed so it's pretty impossible to get redness from this professional exfoliator. Instead you will end up with baby soft skin and a lovely glow.
Probably the most popular exfoliating pads are the Dr. Gross Alpha-Beta Daily Face Peel. They are a combination of 5 different types of glycolic and salicylic acids for ultimate skin sloughing without undue irritation. I have to say nothing makes my skin look as good as these pads do - they are a must have! They can be used every day for normal skin, or a couple times a week for sensitive - they will work for virtually everyone.
REN Glycol Lactic Radiance Renewal Mask is beloved by many. It is a potent exfoliator comprised of fruit acids and enzymes that gives spectacular results. Even better, it is all natural with none of those nasty parabens or sulfates. I have yet to meet a person who has tried this and found it lacking - so put it on your shopping list!
No one wants to have skin that looks thin and irritated, and flakiness is for the birds. So go ahead and exfoliate - any of these products would be a fantastic way to go - but please just don't over do it. Like everything in life, moderation is key.