Just to say to you to be carefull, Use the epsom at every second feeding now you dont want to over dose her with the mag by using it every feed, also your sure to get a salt build up in the bottom of your pots, this is really bad. so it easier to let it wash out by not using on every feed just use it on every other feed. Use the molasses at every feed its about the time now for you when they really start going heavier on the calcium. It seems to be mg more so at the start and then in late flower they really hit on both but more so the clacium from my experience so far.
Hope that makes sense
Edit: Shit sorry man forgot to answer your question on the flushing, well to be honest i have read some journals where people dont flush at all and they havent noticed any taste difference, but i still think that it cant be good for you, smoking whatever the plant has been taking up especailly if they are chem nutes.
So in my opinion i dont need to flush for two weeks, i figure one week will be enough to get out most of what the plant has taken up, so it will taste fine and will be safe. Usually the second week of flush is when the plant has gotten rid of all its nutes and now is using whatever is stored in the leaves.
Besides a second note, if i was doing this on bigger and a strain that would take longer i would flush for longer because she would be a lot bigger and take alot more time to get all of the nutes flushed out.
With the BB and PL they are medium strains so they are not very big in soil grows so to me they just dont need as much time for a flush.
I hope you get what im on about this is just my personal opinion doesnt mean im correct.