Qi is simply an expression for energy. Not some mystical energy or anything like that. Simply the energy we get from eating food, from sleeping, from breathing... If someone is said to have "weak qi", it simply means that they have low energy levels. This can come from poor diet, lack of sleep, lack of exercise etc etc... If someone has "strong qi", they are in good health, "full of beans" as it were. They eat well, get enough sleep, keep healthy etc etc. In terms of martial art: Qi, as I say, is simply energy. Being fit and healthy, in good condition. 'Qi' is not directly used to fight an opponent. Your "energy" has to expressed in a certain way, and we call this "Jin" (not "jing", as this is 'essence', most commonly sperm in Daoist Alchemy practices). There are, obviously, different kinds of Jin (refined power) that produce different effects. IMO, none on these effects include 'no-touch' - unless you count psycological factoring, intimidating the opponent etc... In terms of Dian Xue (dim mak): Contrary to popular belief, this term does NOT mean "death touch". Dian Xue roughly translates to 'cavity press', and refers to precision striking techniques, whereby a practitioner attacks the vital spots of the body, such as the temples, the nerves on the neck, the kidneys etc.. Some points from TCM are also included, although I have no experience regarding this, and have only anecdotal evidence that suggests these points are indeed valid, in terms of causing major damage to an opponent.