i ordered an acrylic stand (its on its way) to put an 8inch and 10inch cake on top of the 10 inch circle, and i i want cupcakes on the following 3 tiers, but is the weight of my cake okay?
That will depend on the strength of your acrylic/plexiglass, or should I say its thickness. Since they vary in size, its hard to answer at this time. The thicker the pvc (which is the material used) the more weight it can hold.
Also you don't mention how much you cake might weigh.