No. Your Ghost site will run fine (for years) without intervention.
If you want to update Ghost in the future, it's easy with a Ghost update.
Gloat offers Ghost maintenance package if you want to added daily backups and more frequent Ghost updates.
If you set up members or send email newsletters, you will need to pay for emails via Mailgun, which cost $0.80 per 1,000 emails (after a three month free trial).
Other than that, there are just Stripe processing fees for any payments and your yearly cost for your domain.
Yes! You will need to first use the Ghost plugin to get a Ghost-friendly export file. I can then import the content for you.
Substation is a separate product and can be bought here.
Installing Substation (or any other theme) is included in the installation package.
No. During the installation, you just need to create a new A record and point it to your DigitalOcean server's IP address. Super simple.
Yep! Adding themes is part of the Ghost installation packages.
Not yet, but I'm looking into it!