That's a good buildpath but that depends on the game imo. PD after buffs sure is a viable item on draven but I think it's very situational. I would always prioritize damage items and focus on burst. As for when buying PD, I believe durign games when you need to kite a lot agaist a tankier comp. As for other games it's a good choice to sell boots for an item like PD or RFC (I prefer this one because of the additional range). Concerning your buildpath, I believe that Collector right now is very expensive compared to other items, and if you are not snowballing you lose gold for damage value. I really believe that LDR is more important than collector especially later on in the game, so with your buildpath i would mostly go BT>Edge>LDR> then depends. I will later publish a new section in the guide because I have been kind of busy lately but for max damage early in game when snowballing and no poke enemy team the best item trio is Edge>Collector>LDR. By the time you have these three items the game is already over, you can also swap collector with edge as a first buy depends on how much gold youhave on base. If on first back you have 1300 just go for BF. Nevertheless I believe items like PD or RFC should be bought only if you are in a situation where you need more space between you and your opponent's. If you can just run them down go full damage, and ofcourse you can swap boots for PD since draven has high ms eitherway.

And in some matches sell boots and get Phantom Dancer.