Per the Wiki, Evasion has a chance to dodge all damage, even damage from surprises in dialogue. To best of my knowledge Evasion still works on dodging the med bay damage, if you roll lucky on your chance.
Mages have the toughest time with getting the second trait point. They have the least amount of health, and speacil skills that can help. But, toss on some poison protection gear, and use a strong poison resist potion and you should easily get your poison resistance in the 110 to 200 poison range (110 resistance lets you take 25% damage, 210, makes you fully immune).
Even without investing in Endurance, it's still pretty doable for a mage to get that second trait point. You might have to swap out your gear for poison protection but very doable.