I'm planning to purchase a fridge dedicated to aging and fermenting. Since fermenting temperatures will range from roughly 50-68 F I'm wondering if the upper range of the 60's might adversely affect the bottles of beers I'm aging in the same fridge.
Keeping the temps in the 60's should be fine...my basement (where I also brew) is a fairly constant 60 TO 65°F year round and that's where I store most if my beers (more than half of what I brew is designed to age for 6 months to a year before bottling or consumption; most are kept at cellar temps, and a few get cold aged).
What you want to avoid for long term aging is a wide fluctuation in temperature...that could encourage deterioration of the beer over time.
Depends on how you're aging beers now, but I don't think it will hurt them. I aged beer in my garage for three years by simply leaving them on a shelf (temps. ranged from low 50's to high 80's) and they kept just fine. I'm inclined to think that aging at a constant, cool temp. would be more of a help than it would hurt.