Q.ZZ plants
I have an old ZZ plant and it appears to have a bloom forming on it. Does the ZZ plant ever bloom?

Yes, but rarely, so congratulations!
The plants will flower and the time for flowering is usually in mid summer to early autumn. The flowers a small and tend to vary in color from bright yellow to brown or bronze. The flowers are usually hidden among the bases of the leaves and are usually not considered particularly attractive. They can be removed without damaging the plant.