Thinking of allowing Strahd as a warlock patron

Are proficiency bonus added to all ability checks including initiative?

How do you deal with a fighter who sneaks up to a guard and attacks the guard?

Also Primeval Awareness is arguably the worst class feature in the game…

Do PCs need to take a long rest before leveling up?

Do you count summoned creatures to calculate the CR difficult?

Should I do a new card reading at the start of every Curse of Strahd session?