Would you allow this to be used for $1 dollar purchases, like the train?

I said no, such items are too inconsequential to be paid for with credit, they need cash.

"instead of spending $2" probably means "up to $2" so it's allowed. Maybe your high credit has made you popular with the more wealthy passengers and they pay for your ride.

However, if you're ever required to spend money, does this include using Credit Rating? If you went to the Curiositie Shoppe with $3, and the cheapest item you drew was $4 or $5, are you required to purchase it since you technically could? Or could you opt not to buy because you technically have only $3 and can ignore your Credit Rating if you so choose?

Same question applies to the Addiction madness card.

I think so, yes, in these cases i allow a 2 dollar reduction.