He never intended to cheat on Roxanne. He was just using Barsine to enjoy Roxanne's possessiveness for himself. Even he knew, it was just because of her insecurity as the Queen, but at least that gave him a sense of happiness seeing Roxanne fighting for him and a facade that she reciprocates the love! After what happened on Friday, the first thing he would want to do after waking up would be meeting her. He has got what he wanted. He now knows that Roxanne has finally accepted him and also that she needs him in her life so Barsine is now useless for him!
He will just marry off Drypetis and Hephaestian but he won't pack them away.Then he would go to search for the route.
Barsine currently has two complaints against Alexander. One, he has enslaved the Faarsis and two, he fights to snatch other's belongings. Since the CVs are going to turn him back towards Macedonia just after the Battle of Hydaspes and after getting on friendly terms with Porus, we can see a reformed Alexander. Reforming Alexander is essential for Porus's glorification so I am nearly convinced of this particular outcome that Alexander might declare it to Barsine that Faarsis would no longer remain slaves and would be given equal rights and she might resolve all her issues with him completely when he would return PR to Porus. Through this, I can still see a ray of hope that Barsine would not be responsible for his eventual death!!
He won't pack her off because she needs to be there till the Battle ends to resolve her issues with Alexander. We might get a voice over that Roxanne killed them after Alexander's death.
I don't think that Alexander would ever come to know of that Rakhi. The CVs put certain lines echoing while being said when they need to prove it a 'patthar ki lakeer' in a sense.š Like when Olympias said, 'Ab tumhe hi kuch karna hoga Roxanne nahin toh Alexander ki Porus ke haathon shikast taye hai'.. it evidently pointed towards her Rakhi which would become the reason for Alexander's victory! Yesterday, Roxanne's lines, 'Agar aap chahengi Mallika toh yeh baat Shah ko kabhi pata nahin chalegi' had the same editing effect, so I believe, he won't ever come to know of it! So it remains to be seen what would make him return PR back!