Let's see if I can answer most of this.
1.) At closing, you could just put the store in Catalog Mode through the addons section of the admin. People will still be able to browse your products, but there won't be an add to cart. You might be able to get some automated way of doing this or doing with a cron job or something.
2.) A html block or banner would be good for this.
3.) I could have sworn there was an addon available for sale that could do this, but I can't remember who was selling it. Maybe someone will post on here.
4.) I'd think you could use User Groups for this. Then one group would be your normal customers and the other would be your annual membership people. The pricing for the annual membership people would just be lower.
5.) Just set your manufacturer as an extended feature and put in their URL. I don't know if the new version has the URLs clickable or not, but it is easy to add if it isn't.
6.) I'm not sure about that one. You might have to talk to tbirnseth (Tony) or Alt-Team about doing this.
I hope that helps,
Would the built-in Reminder Notifications from the Recurring Billing Addon handle your needs if setup with an annual plan? I don't use this although it looks as if it may do the trick.
Notification duration - Number of days preceding the payment when the subscriber starts receiving reminders.
[url=“CS-Cart Documentation — CS-Cart 4.15.x documentation”]CS-Cart Documentation — CS-Cart 4.15.x documentation