by actually limiting the supply, there is already a limit, as I stated before, a maximum of 21M of max supply but if you are talking about the distribution of bitcoins, it is also has been stated before that there is a halving year which it will decrease a block by 1/2 of the current value every 4 years
no, every 4 years the number of bitcoins in 1 block will reduced by half the current amount, today 1 block = 25 bitcoins, in 2016, 1 block will be 12.5 bitcoins, this is about limiting the distribution of bitcoins
Supply will effect the price if only there is a real demand to it, because if there is no demand on it, it will be known as abundant supplies
i.e If you got 10 candies but you only need 1, then the rest 9 candies will be worthless as it has no value, and different cases is if you got 10 candies and you need 11 candies, the value of each candy will rise
then each candies will rise in value, because everyone will be pursuing this , the main reason of price increase is the buy power, if something is valuable enough , people might start buying it, if there is alot of buy power, the price will drive higher, remember, in every buy there is a sell, someone who bought lower will sell it higher