Yes you can make clothes for Minis, but it is much harder than making clothes for regular sized Pullips. It's difficult to work on such a small scale and clothing can often turns out poorly fitting. Still it can be done, you might want to start off with something simple, like a hat, then work your way up to making a dress.
Here are link to some patterns (they're actually for Petite Blythes but will work for Minis too):
On mobility of Minis:
Minis have very basic articulation on the neck, arms, legs and waist. The legs have wire in them so you can bend them very slightly. Minis don't have the blinking function either.
I highly recommend purchasing Minis though. I have two now and my very first Pullip was a Mini Swan. They are very cute. You'll have to watch out for flaws though. Early Mini wig quality is not very good, some Minis will snap at the waist (Froggy is more prone to this) and Minis with dark clothing will most likely have body staining.
Hope that helps!