Hi, Sohil. Yes, meditation develops that ability to manipulate sensations, feelings and intentions. Exploring which physical/verbal/mental actions lead to which mental consequences so that you can fashion skillful mental states is in a sense the whole of the practice. The goal is to head for more peaceful, still, concentrated states of mind, and the final goal nibbana can be described as complete freedom from all fabrications. A lot of people get ahead of themselves and try to experience freedom from fabrication too early, by attempting to simply drop all fabrications. However, on the way to that final goal, you have to fashion skillful fabrications in order to tame the hindrances and bring the mind to peace, stillness and concentration. Metta is an example of such fabrication: fashioning it is a way to bring ill-will to an end. So if you find yourself doing things in your meditation in order to manipulate your mental state, that is not in and of itself a sign that you're meditating wrong. It's always good to check with a teacher, but the key test is always whether the results of that manipulation have tamed the hindrances and/or enhanced the factors for awakening.

You would probably gain valuable perspective from that Thanissaro essay I referenced in the other thread, and the Food Sutta on which it is based.