The regular green P. afra is quite common around here. Not as common as the jade plant but definitely the runner up with that growth habit. It is incredibly drought tolerant in the ground, incredibly amenable to pruning (and thus used as a hedge), incredibly easy to start from cuttings of almost any size.
It will grow different in the ground, and it will grow different when pot size is limiting. The potted plants you may have seen with really wide trunks were probably grown to that size in the ground (or a huge pot) and then moved to a smaller size pot (more likely restarted from a cutting) to achieve a dramatic effect. Really wide trunks don't really happen (except maybe over the course of decades) when pot size is limiting.
My advice would be to provide more space gradually and not all at once, and pay close attention to how the plant grows after it is repotted so you know when and how that works best.
The variegated form has a different growth habit, less upright and bushy, more low and trailing. Feel free to prune the green version and shape it for bonsai if that is something which interests you.
Flowering is not something you can necessarily expect. The plants in the ground here will do it most years in pretty spectacular fashion.
My big potted plant (~3 feet tall) has bloomed well some years but not at all in others. I do not understand what is required but it has nothing to do with having lots of abundant nutrients (though surely there is some minimum needed there). I am guessing maybe the weather or the amount of rain we get in the winter might play a role. The flowers attract bees but I have never seen birds stop by.
