I just bought some Black Alex DX-32 Rim: 26", 32H for my Big Dummy and I was wondering if they were going to fit my Fat Franks. Or did I just make a dumb purchase?

According to Schwalbe, a 54mm is good on a 29c rim, so 60mm (2.3") should be OK on a 32.

Unless the Alex listed dimension is outside width. The Schwalbe recommendations are for rim width between the beads inside the rim which many rim makers do not list. Normally it is about 5 to 6mm less than the outside rim width.

I am more confused now.

Measure the inside width of the rim. Theoretically the tire width should be within 1.4 and 2.0 times the rim inside width per ISO standards. This is frequently exceeded even by bike manufacturers who fit wider tires than ISO recommends for a particular rim width. For some of the really wide tires it is hard to find rims as wide as ISO recommends.

I would not expect a problem.

I am patiently awaiting the rims to arrive. I have thought about getting them powdercoated to match my snapdeck.

I've mounted fatter than recommended tires on rims and had no problems...the issue is really that really wide tires on a narrow rim can exert a lot of force if inflated to high pressure which can damage the rim or blow the tire out. Of course you don't need much pressure in a high volume tire so unless you make a mistake filling the tire with air this isn't much of a concern. You can also have issues if you corner hard with very low pressure, but again that's not going to happen unless you really under inflate your tires.

I bought the above mentioned rims because I didn't like the way my fat frank's looked or performed on my Mavic 717's. I thought with a wider rim it would be better.

Those rims are plenty wide, They'll be fine. I run big apple 60mm(2.3") tires ghetto tubeless on a mavic ex325 with no problems. 32mm outside width. I find 1.1 to 2.2x the rim's outer width is a good rule of thumb for tires.

Received the rims; now just waiting on the hubs to arrive.