How oil price can influence Bitcoin price?
Easy through electricity. Electricity will go down and price of mining will be little cheaper. Cheaper block will influence more hashrate! BTC price will increase!
My opinion.
Price will actually go down because more hashrate increases the supply with increase driving the price down.
the halving is there for this reason, to reduce the pressure from the miners, which with their margin i don't believe is very high, they ar enot selling 3600 coins per day
and it's the price that drive the diff up not the opposite
Yup. The more hashrate is added to the network the faster the difficulty increases, leading to miners quitting, then the cycle repeats. The block chain rules regulate the rate of inflation constantly, so the price should never be effected by difficulty, except in an irrational way. Such price affects should be short-lived.