I've made a RKT ball that is going to sit on top of my 2 tier cake-it's an 8in & 6in. My concern is that the weight of the ball may cause the ball to slid down the dowel and that the dowel may poke through the top of the ball. Is there something I can do to hopefully keep this from happening? I've never made anything with RKT before. I did pack the RKT very tightly and I've put the ball on top of a small cardboard disc that I covered in fondant. I'd be grateful for any help! TIA

I'd use melted chocolate as a glue on your dowel. I'd fill the hole in your ball with the chocolate, insert dowel and let cool. You should be good. And only insert the dowel no more than half way through the ball. Any more and you risk it poking through.

I just made my first teapot cake (in my pics) out of RKT. It was heavy and I had similar concerns as you but what I did was place 3 leveled and cut dowels in the round 10 in below it and then placed my teapot on top, using a dab of buttercream as "glue" between the teapot and cake. The teapot was attsch to a thick small foamcore board that had a hole precut down the middle and also covered in fondant. Once the teapot was on top, I put a skewer thru the teapot and cake itself. It held together pretty well. HTH.
Fedra