Thanks for your questions. Sorry to say that I don't think anyone has the official EA instruction manual so I don't really know how everything works. I don't understand what you mean by "T/L", if you are asking about the Trailing Stop Loss functions, all I know is that it will only start to work only when the trend is moving in your favourable direction. If the trade started but the trend is moving against you, then the trailing stop loss function won't be triggered or activated to work at all. Secondly, for the "Trailing Stop", if value is set at 12.0, not sure I'm right about this but, I think what that means is, let's just say that when a EURUSD BUY trade started moving in a profitable or in your favourite direction which is upward movement and once it has reached 12 pips/points in profit, then the Trailing Stop Loss function would immediately be activated and started to move your stop loss level to 12 pips/points below your current profit level and so the distance between your take profit and your stop loss is 12pips/points. If that profitable trend continues to go up to say 25 pips/point, then the "trailing stop" will also follow this trend by move up your stop loss level to 12pips/points below 25 which should be at 13 pip/point level. The trailing stop loss level will only go up and won't come down in a BUY trade condition (if it is a SELL Trade then it's vice versa). Therefore, it will help protect and secure your profits when the trend is moving in the positive directions. Even when later if the trend of the BUY trade suddenly changed direction and start to keep moving downward, then the EA will eventually and finally close the trade at the 13 pip/points level which is the final Trailing stop loss level and you'll end up earning a profit of 13 pips. That's roughly the way of how the trailing stop loss function works in my understanding.
As for the "Trailing Steps", if the value is set at 1, then the trailing stop loss level will move every time whenever the trend started moving 1 step in your favourable direction. If you set the value to 4, then the trailing stop loss level will only move once every time whenever the trend has moved 4 steps further in your favourable direction. There are pros and cons of what value you put in your Trailing Steps, sometimes it could possibly be better to use a smaller Trailing Steps value so that the Trailing Stop loss function will follow closely with the trend. Yet the problem is, if it follows too closely with the trend movement, then there isn't much space for the trend to fluctuate freely and the trend could possibly changed direction and hit the stop loss level too soon before allowing itself to go further in your favourable direction which could eventually end up earning you with a larger profit. So in short, there are always pros and cons of how big or small value you set to the "Trailing Steps". There is no right or wrong about this matter. Some people might like to do their adjustment by changing the value frequently as they deem fit, some just don't anything and leave it as it is. It all depends on what you prefer according to your own strategy and preference. It's that simple.
Hope that helps. Please bear in mind that I'm not an expert in any part of this and I could be wrong at some point or so. Therefore please do your own research and study on how Trailing Stop Loss functions work and what are the pros and cons of using Trailing Stop Loss. I believe you can simply do a google search on this topic for your better understanding.
Ok that's all I can say about this matter. Wish you and everyone all the best, take care and God bless. Bye.