Changing te price of a yearly membership in the middle of a cycle

Hello. I have two questions about the Membership plugin. I am using the PayPal Standard Payments gateway with automatic renewal. For the Subscription, the Mode is Serial, and the Period is 1 year.

Question #1:
A user pays for membership to my site for $50.00/year. A few months later I decide I to increase the membership fee to $75.00/year. When the user's membership auto renews after a year, will it be renewed at the $50.00/year price of the subscription (which was set when he originally signed up), or will the membership be renewed at the $75.00/year price (which I changed it to during the middle of his cycle?) If his membership auto renews at the original $50.00/year, how do I get him on the $75.00/year payment schedule?

Question #2:
For the Communications feature, I set the Pre-expiry period before expiration to 5 days. If after a user purchases a membership I decide to change this Pre-expiry period before expiration to 10 days, will the user receive the reminder email 5 days before expiration like it was set to when he first purchased a membership? Or will he receive the reminder email 10 days before expiration, which is what I changed the Pre-expiry period to AFTER he purchased a membership?

Thank you.