First thought: you're crippled by lack of available upgrade cards. Proxy them so you're actually learning the game everyone else is playing.
Marksmanship is one of the worst upgrades in the game. You spend 3 points and a valuable upgrade slot for the ability to get one crit instead of a hit when you spend a focus token, except it comes in the form of a special focus token that can't be spent on defense. Predator is better at doing the same thing for the same cost, but just about any
EPT option is a better choice. R5-K6 is also pretty bad, once you have predator you won't ever be using target locks. You'll probably want BB-8 here instead, to make sure Wedge gets his shot.
On a card access issue, you always take integrated astromech or guidance chips since they're zero-point upgrades.
X-Wing- Red Squadron Pilot w. Proton Torpedoes & R5 Astromech- 28
This is just a bad ship.
PS 4 is not relevant (you're still lower than the aces, and you have no maneuvering actions to abuse lower-
PS generics), and you vastly overpay for it. Then the R5 astromech is trash, you won't be alive long enough to get any value out of it.
A-Wing- Tycho Celchu w. Push the Limit & Homing Missiles- 34
And here's another place where you're crippled by lack of upgrade cards. The Rebel Aces expansion gives a-wings a second
EPT slot for free, and autothrusters is abusively good on any ship that can take it. Tycho isn't a great choice (he has zero firepower once the missiles are gone), but at least with the mandatory upgrades he's not going to be complete dead weight.
and have been considering trading Wedge for Biggs Darklighter backed up by R2-D2.
Trade the useless red squadron pilot instead. For 26 points you can get Biggs, a throwaway 1-point droid, and integrated astromech. For 29 (dumping marksmanship from Wedge) you can get Biggs with R2-D2, which is not as efficient (Biggs usually dies too fast to regen
HP) but can be good. That's way better than the red squadron pilot, and keeps Wedge shooting longer.