Supply:
Supplied by miners. Any serious operation NEEDS to sell to pay utilities. That creates a steady supply of bitcoins offered at market price on a regular basis.
No they are introduced by miners, and supplied by miners and anyone holding Bitcoins. Supply is not a problem.
I must object. High supply
is a problem if you want the price not to drop (which is implied by OP). A lot of miners decided to join when the price was at $30. They mostly joined for a quick buck, not because of bitcoin and it's features (see troll post above). These people have to throw their mined coins to the market, to recoup their investment and pay utility bills.