They are similar, but let's look at the differences. "Kick around" means to consider, but only offhandedly or casually. E.g. We were kicking around the idea of changing meeting room 2 into an office, but never went anywhere with it. "Think over" means to consider, but only by yourself. E.g. Please think over the two treatment options and contact me as soon as possible with your decision. "Talk over" means to consider, but only together. E.g. The wife and I talked over having kids already and just aren't ready to commit yet. In the above examples, I think it's pretty unnatural to swap in any of the other choices. Even where it's maybe possible, I don't think it's as good a choice.