EA for scaling into positions

Hi, I am looking to create a simple EA that helps me to scale in/pyramid into my existing position. It need to be able to open multiple positions on any timeframe on any symbol/pair. It needs to be able to calculate position size as a % of the current balance, trail stop loss (SL) levels, hide SL and profit target (PT) levels. Further details will be provided once you have indicated interest

So these are the main things, the EA needs to do,

• 1.      Automatically trail the SL levels as each position is triggered in.  
• 2.      Trail the SL levels of all the positions together
• 3.      Calculate position size as a % of the current balance
• 4.      Set SL and PT levels and hide them from broker
• 5.      Time filter to set the duration when the EA can add positions
• 6.      Close all positions immediately together
• 7.      Used on multiple symbols/pairs simultaneously