The directive to remove is NAT, as the impact is fairly small, exploiting the narrow window early game where the corp doesn't have perfect control over its agendas, largely after that, double access from HQ is not that great. The 'drawback' is at its worst, due to HHN.
SF is the best of the 3 in the most situations, a free draw engine, especially one that triggers when you need it, is amazing.
ABR is the most impactful of the directives, its ability to break ice early slows down the corp, and late game can be impactful to save you $$$ on lots of things.
The only way to go besides cutting NAT and putting it in your deck is to cut ABR and put it in your deck, and lean on overmind early.
This directive probably isn't enough to bring Adam to playable, not any more than before sadly. However stealth does look much better now.