Trying to answer your querries one by one Taurus ji.
There is only one rule to initiate a trade. Both Price and OBV should be on the same side of 200EMA.
Since you can always know when the price(and between price and OBV you can know when price would breach that level) would flipover to the other side of 200EMA, i stay in wait for it (I pre-empt not discretion) and put an order when we are about to approach that value. We can do so by keying in the exact value of the 200EMA, or the last pivot low below 200EMA (in case of shorts) / the last pivot high above 200 EMA. Your SL in either case is already established as the preceding pivot high (for shorts) and pivot low (for longs). It is upto you whether you want to take the trade as per your risk appetite. For taking profits you can have a pre-defined greed level say 50/70/100 points or you can trail it by using the 36EMA, or anyother method you deem fit. I hope your querries have been addressed.