Questions about moving my domain over to Dathorn

[earth-friendly]

I started my Dathorn account several months ago, and I've been dragging my feet, but I'm just about ready to move my domain name over to Dathorn from my other webhosting company (changing the DNS pointer). I'm somewhat of a newbie at this, and I have a number of customers who order products from my site, so I'm pretty nervous about doing everything in a safe way, so that I don't lose customers.
So, I have some questions -- I'd really appreciate some advice on these issues.

Previously, I had access to a separate secure server where I had my shopping cart. At Dathorn, I will be getting a secure certificate installed for my domain. So I will have http://www.mydomain.com and https://www.mydomain.com.

1) Can certain directories be used for both http and https (like an images directory)? Or should I have 2 separate directories for the images, one used for http and one used for https??

2) For the shopping cart scripts, I need to make sure they are run only under https. How can I force a directory to be https if someone types in http?

3) While the DNS changes are propagating, I plan to disable the shopping cart on both webhosting servers, just to avoid unpredictable behavior. Does that make sense?

4) How soon after I change the DNS entries can I request the secure certificate to be installed? Do I need to wait for the DNS changes to finish propagating, or can I request it to be installed right away??

5) How can I be reasonably certain that the DNS changes have finished propagating, so I can enable the shopping cart?

6) Are there any other issues that I need to worry about?
I've tested everything as well as I can, but I can't completely test things until the secure certificate has been installed, and I want to limit my downtime as much as possible.

Thanks in advance for any help with these issues!

[AndrewT]

1) Both the secure and non-secure content is loaded from the exact same folders.

2) You will have to setup some sort of redirect to handle this.

3) Yes.

4) Generally it is best to wait at least 24 hours or so.

5) You do not need to wait for this, you can enable the cart as soon as the SSL is available. Just make sure that the version on the old server remains disabled.

6) It seems like you've got it all covered....

[Jonathan]

For the redirect read this link....

http://forums.dathorn.com/showthread.php?t=1629&highlight=redirect+http

[earth-friendly]

Thanks very much, Andrew and Jonathan, for the quick responses!
I've posted a notice on my website letting people know about the upcoming downtime, and I've set the transition time for 2 weeks from now, so people can get their orders in.

Hopefully, everything will go smoothly, but I may be back with more questions.