Yes, just select monthly above.
Yes, you can try out all of the functionality, but it'll be limited to 15 records until you subscribe. Install the Google Sheet extension to get started: https://gsuite.google.com/marketplace/app/sheet2site/554447131316
Yes we do. You do not need to pay extra for hosting.
No. You would need to buy it yourself. It cost ~$11/year for a .com
Yes you can easily change the template from the Google Sheet after you already started to work on any template.
Yes it is. More detailed here.
Yes you can! You can use ImportRange formula or just copy the data from your sheet.
You can use the embed feature to embed Sheet2Site page on your existing website. For example, you can connect your sheet2site to a subdomain like page.example.com, or embed it on example.com/page.