After an unfortunate incident with my 5th level paladin, where I got 1 shot by a zombified beholder in barovia while the cleric wasn't at the table, I decided I should make a more self sufficient character. My idea was to be extremely hard to find and hit, while having very good perception and saving throws. Once I catch up to the rest of the group in level I will be the primary scout and trap finder/disarmer. The main things I want advice on is whether it's worth waiting that long for dex increases in order to get feats(I'm not concerned with damage output, only surviving), and good warlock utility spells. For cantrips I was thinking Minor Illusion and Prestidigitation/Mage Hand, and for 1st level spells Hex, Protection from Evil and Good, and Unseen Servant. I'm not planning to have attack spells because i'm never going to get any more charisma to hit with. The last thing is whether or not it's worth reducing my wisdom, and therefore perception, to get more constitution. I'm thinking I want as high as possible to find traps better, but I don't know if there are any traps late game that need so much. The other thing is that I don't know how many constitution saves i'll have to make, since I'll mainly be either stealthed and scouting, or hidden and shooting once per turn with a heavy crossbow.