Definitely open to balance suggestions. Especially on K-2SO. I feel like it can allow a lot of shenanigans.
BB Unit
I think this one is fine for X-wings and Y-wings and could stand a chance at making X-wings almost as good as a B-wing. It is not as good as BB-8 because it doesn't give you a free action. It could make Rebel TLT Y-wings more tempting over the Scum Thugs. 1 point less than Vectored Thrusters but much more limited and takes up an astromech slot.
C2-B5:
Empire only. This is the new Evil Astromech in Rogue One. He is C-3PO except for your red dice. I can see it being pretty powerful guessing 1 on something like RAC with Palp. Guess 1, get hit, focus, blank. Add a hit. Focus to Crit. Palp Blank to Crit. I think the price is fair since it is not guaranteed and doesn't work on both gunner shots.
K-2SO:
I like the idea of this card. K-2SO in all of the trailers is just a calm team member in the face of constant danger. I am concerned that allowing target locks could be an issue with K-turns + Torps. But then again, Rebel missile/torps aren't really impressive currently. I think that this might be worth anywhere around 3-5pts.
R4 Astromech:
This is my idea for an X-wing fix. It is not going make big names like Poe better, and most of the time, people will probably still take R4-D6 on Biggs. So this is really for the cheap generics. Having that extra integrated health on a 21 point X-wing will make them good enough to really consider taking. It also encourages X-wing or Y-wings to take a torpedo, which no one does.
S19 Astromech:
In the fluff, this is a super versatile and can be stripped out and inserted with a shield generator or a gravity well (to protect the ship from enemy attacks). So I obviously wanted an agility and a shield side. I also decided on a crew slot because Dengaroo. It can help Manaroo a bit, but Dengar isn't going to take this is his crew slot. It is scum, so it is a bit unreliable. Depending on the list you fight you can pick a different side. If you are playing against a swarm, the extra agility and the risk of it breaking is probably better. If you are playing against a spike damage list, you probably want to make your first pass, take a ton of damage from 1-2 shots and escape to regen shields. I am tempted to make this 3 points because its not super reliable and add a chance of the shield regen breaking. But this is where I'm at with it for now.