I have dry skin with a somewhat oily t-zone, hormone- and stress-related acne and that flaking, but blackhead-riddled nose problem, too. I used to have oily/combination skin when I was younger and used harsh products for oily skin with no problem at all, but I became both significantly drier, more sensitive and more acne-prone around 25. I couldn't deal with it at all at first, everything that used to work against my acne made the rest of my skin dry, itchy and flakey with horrible dry spots popping up everywhere, along with even more acne.
It became better first when I started treating my skin as dry, not acne-prone; that made the acne go down significantly, too. I wash with a simple, pharmacy brand cleansing lotion for dry skin (or MAC Cleanse Off Oil when I can afford it, it's great stuff for dry/combo skin), rinse with water and moisturize with Eucerin 5% Urea Cream for very dry skin - it's rich and very, very hydrating, but not at all heavy or greasy. Regular use makes my skin behave more like normal/combination skin than dry skin, no dry spots other than in extremely dry and cold winter weather, and makes it possible for me to treat the acne. I don't know what I'd do without it.
I think the nose flakies could be seborrhea rather than dryness, though. I did some experimenting and noticed that they would disappear if I rinsed off my cleansing lotion with water twice a day, but got worse when I babied my skin and rinsed with water as little as possible, which points to it being caused by something other than dehydration, at least for me.