1. Position is the most important thing
It is not. The most important thing is you have to know how long you should let your position open. You should know you have to close your position, accept a loss, minor loss, a draw. If you can not accept it and let your position opens forever, you will be liquidated.
2. Always set the profit/loss ratio above 1:1 (2:1, 3:1)
Profit/loss ratio is 1:1 is bad and in my opinion, 3:1 is the ratio to use.
4. Do not borrow, deposit too large (under 25X is safe)
No. It depends on the market crashes or not and your entry price, your stop limit, stop loss order.