Need a simple EA to change order PL based on time and limit orders

Hello,

I need a simple EA to do below jobs.

A) Keep monitoring open positions. If a position has run for 1 hour, change its PL to 10 pips. After 5 hours, change its PL to 5 pips. After 12 hours, change its PL to 2.5 pips. After 24 hours, close the position whatever it's profitable or not. If profit is equal or larger than new TP when modify the PL, close the position instead of modification.

B) Check if the margin level will be less than 400% if a new position is open. If it will, reject the position, do not execute the order.

C) Only allow one sell and one buy orders. Do not let two sell/buy orders execute, even though they are in different symbols.