Do you have to use all available benefits of a card at one time or can it be split up during a turn. For example with an Old Friend, which give you an extra action and lets you spend one coin. Can I activate it to get the extra action and then later spend the one coin, or does it all have to be done at one time? I ask this question because it could happen that you are down to zero cash and have to sell a property, but need the extra action to do so. You then can't spend the coin until the property is sold and you have money. Is that allowed?
The bottom centre and the top are independent. Technically, you don't pull the card down to show you've used it when you do the bottom centre to take the extra action. You only pull it down when doing the top right portion. This allows you much later to do the pull down and spend a $1, etc.
Personally, I don't like that rule, as it's very easy to forget you've already taken the extra action, and then later in your turn take it again when you slide the card down to spend the $1.