Questions about Supporter plugin

I have a couple question about supporter functionality and how to use it in a use case alongside MarketPress.

What happens to a blog's Supporter features (plugins, space, themes) when their supporter term runs out? I have it set as recurring billing so I shouldn't have too many expirations, however, if someone cancels their payment and their Supporter term expires, do they loose access to the the features they were using? Do the plugins automatically deactivate?

I noticed on my test blog that the theme is grandfathered in (meaning, activate during supporter and when supporter runs out it stays active). How many of the Supporter features are grandfathered in?

It makes sense that some features are grandfathered, however, if someone signs up, then cancels and still has the ability to use everything there is nothing left to encourage them to pay again.

Second question, by default in MarketPress (which I am using as a Supporter plugin) I am using chained payments through PayPal. I do, however, want to offer the other payment gateway because the need for them has been specifically requested by my community. I want to offer them as a paid upgrade (a sort of Pro account). The scenario I want is that, by default, users must use chained payments, however, if they want to get away from sales commissions to us, then they have to pay a higher monthly/quarterly/annual fee to get access to the higher functioning payment gateways.

Is there a way to do this? Do the Membership or Upgrade plugins link in with MarketPress enough to offer a scenario like this?