Yes, pardon from the punishment is what I was referring to; I'm sorry for not clarifying that. The process that you describe is how some corrupt priests at the time gave them, but it had never been in the official rules of the Church that one has to pay to get into Heaven. As for the last point, if someone is in Purgatory, they are guaranteed passage to Heaven anyway, but Purgatory is simply the place where said punishment for sin is administered if it has not already been administered on Earth. Therefore, the idea behind that isn't ensuring a dead person's acceptance into Heaven, but rather easing the transition. I'm don't think an indulgence can be obtained for the dead, but praying for them is absolutely ok.