May seem like an easy answer but I would like to use my Discourse site as my entire site. I know that I can forward/redirect my domain name to my discourse community site. Would there be any reason to just launch a wordpress site with a link to the community? I don’t necessarily need a landing page or any other pages at this time. I know that if I do I can just create a post and link to it similar to About / Terms / Privacy, etc.
Is there a way to add a description or banner to the main Discourse/landing page to offer a description to new visitors whereby that banner disappears on all other pages?
If you have a bunch of static content that will be far cheaper to serve via something like Wordpress. A $5 VPS can serve millions of page views with the right caching and optimizations.
If your site is solely about community and interaction, then yes, Discourse is a great candidate.
I run two sites that are just Discourse with customisations.
If you know what you are doing you can customize them a lot to achieve more or less anything.
There are loads of open source Theme Components and plugins that can help you.
The only tricky bit is that if you have very specific requirements and your need to build something very bespoke the front end framework can take time to learn and it’s harder to source developers for (even though it’s very good indeed).
Standard installs are very stable and very easy to maintain so go for it!