Add some functions to my EA

Dear developers,

I've started to develop a simple EA based on a custom indicator. It works correctly, since it opens the trades according to the indicator, but now I need to add some features, that's why I need your help:

-Lot size: actually it's a fixed lot size, I need to simply add a risk %.

-Take profit

-Trailing stop

-Stop loss: basically, I don't need a SL for any opened trades, since I would like that this EA will close the deal once it receives the opposite signal from the indicator and in the meanwhile it opens the opposite trade doubling the lot size. This can happens X times according to the settings (ie. MAX doubling = 4). Once these steps are completed the EA will place a Stop Loss ONLY for this last trade. 

 The code must be clear and commented.

I think the whole job it's easy for you.

Please let me know if my request it's clear or if you need any further info.