2) Despite successfully passing the challenge, the achievement for playing 10 hands of blackjack did not unlock on Steam.
The only console commands I have used ever, were to move NPCs to me, and once to open the old ED-E's inventory (both done post failure for unrelated reasons).
3) I have achieved the Questin' Mark challenge over 5 times now. I believe once it moved onto the second tier, but at some point it reset back to the first tier one.
Edit: Now the slot machine achievement on Steam has failed to unlock.
Edit2: Little Wheel (roulette) unlocked correctly.