Your spinning disc sounds a lot like the classic "Frizbee" toy. There are a lot of variations including ring shaped ones, so in terms of aerodynamics, a spinning ring with the proper airfoil shape should be able to fly in the Venusian atmosphere.
There are a few factors to keep in mind. Unless the structure is very large (many kilometres in diameter), the spin rate will induce a lot of stresses on the people and buildings inside. In the extreme case, the ring is rotating so fast that the buildings are oriented with the "floor" pointing at the outside of the ring and the ceiling pointed towards the open centre, you are creating "artificial gravity" like a space station.
If, for simplicity and to keep the mass and maintenance to a minimum you have the buildings fixed to the floor of the ring, then the rate of rotation needs to be fairly low. People walking inside the ring will still experience forces induced by the spinning, but if it is low enough, they will be able to compensate.
The second issue is "how" the ring keeps spinning. The Frizbee gradually slows down as air friction steals the momentum of the toy after you release it. The colonists are not going top be too thrilled as the rotating forces are substituted for free fall into the depths of the Venusian atmosphere.....
Several ideas suggest themselves. The ring will need a series of motors around the perimeter to drive the rotational force. Since the atmosphere isn't too conducive to combustion (and sending fuel to keep such a large structure rotating will be an immense task in itself), you could have the upper surface being a microwave receiver and solar power sats in orbit are beaming electrical energy to the structure. Some is tapped to run the internal systems and the rest keeps the motors running (probably electric engines spinning huge ducted fans or propellers).
Another way to go about this is to consider a tether from the mining site on the ground. The tether is used to send mining buckets to and from the ring, but it might also be part of a thermocouple system, with the temperature differential between the ground and the ring being used to generate electrical energy. This avoids the complications of a solar power satellite, but the amount of energy will have an absolute limit based on the difference between the two temperatures, and the efficiency of any system to tap energy will always be less than 100% anyway.
For aerodynamic reasons, you want everything to be enclosed in the ring shaped airfoil, since protrusions and gaps between objects will simply induce drag and make spinning the ring much more difficult and energy intensive.
One other consideration for any sort of floating colony in the atmosphere is how are the people going to get too and from space? a spinning ring or a giant spherical balloon like a "Cloud Nine" is going to make a very tricky launch or landing platform.