I used to run Creative Suite 4 on my 2006 iMac perfectly adequately.
The new Mini is over 3 or 4 times as fast as that. Even the base model has the CPU performance that you get from a base Mac Pro in 2009. CS4 was launched in 2008. The Mac Mini will cream any Mac released over four years ago.
There is no danger that any Mac in recent years is not going to be handle any tasks that most people are going to throw at it. The only question is whether is takes 1 second or 5 seconds to do it.
If you're trying to determine the quaternary structure of protein molecules, or making a 3D map of the universe, or rendering the next Pixar movie, then maybe you want a faster machine, in order to save time.
But for most uses, any recent computer is going to cope admirably. Creating gifs for websites is these days a trivial task. Frankly, running 17 Adjustment Layers on a 300dpi 8" x 10" CMYK image is not that taxing either.
Yes, a Mini with a Fusion drive or SSD will be faster, noticeably, than one with a standard hard drive; and the i7 will be faster than the i5 base model. For me, getting the top-rated CPU in the mini is all about "future-proofing" -- making sure that the Mac will be able to cope with the bigger software of the future.
If you can afford more than the base model, then I would still advise getting it, but for reasons other than "which Mac can do what I need". That question has long been answered.