Hello and welcome!
You're touching on a couple of topics, let me try to arrange my thoughts:
- installation through softaculous
- unlimited space hosting plan
- use a community on nakedexpat.com/forum (or similar) versus forum.nakedexpat.com
- replace WordPress on nakedexpat.com with Flarum + v17 Blog
- installation through softaculous
Softaculous is a great tool, it assists webmasters in installating software that might otherwise require more work to install. Sadly the implementation provided only does the installation, there is zero functionality in softaculous to update or install extensions. This voids the hope of just using softaculous for managing your Flarum community.
- unlimited space hosting plan
A lot of hosting companies provide these plans. Usually people never require much space anyway and that's where they make the money. A few clients might potentially use up a lot of space, but this balances easily against the vast majority that uses very little. Understand that in these arrangements there are always Fair Use Policy articles in the terms to protect the company against unfair over usage. There's nothing wrong with these kind of hosting plans though and you can definitely use them.
- use a community on nakedexpat.com/forum versus forum.nakedexpat.com
This is a SEO question really and it's one that usually turns out to be heated. To my limited knowledge, what I've come to understand over the years, is that using a subfolder (nakedexpat.com/forum) makes content count towards the rating of the domain (nakedexpat.com) whereas a subdomain (forum.nakedexpat.com) counts towards the subdomain and partially towards the main domain (nakedexpat.com).
In that regards if you intent to use your community to build content that is mostly on-topic for your domain, then use a subfolder (nakedexpat.com/forum), if you expect a lot of content that will be off-topic or even derails from the topic of your domain, use the subdomain (forum.nakedexpat.com).
- replace WordPress on nakedexpat.com with Flarum + v17 Blog
You mentioned this is not recommended? Please explain what recommendation this is.
Aside from that, the same logic applies as to your subdomain vs subfolder question. Using v17 Blog in your community means that your community will be your website and the content on your community counts/works towards your SEO rating of your site. If what is discussed is mostly on topic, then that doesn't matter much.
In addition, another consideration would be whether you want to maintain two pieces of software. Replacing WordPress will reduce the time you need to manage your site but will take a while to move the content over. Keeping WordPress is probably wiser if you see your community as an addition and not your primary way of building the brand (nakedexpat.com).
I can go on for a very long time I think, talk about WordPress being more mature yet Flarum also doing a great job. But in the end I personally think growing a brand/domain/website is less about these choices and more about building content, engaging with users and enjoying yourself.
If you have any further questions, I happily go into more depth.
PS you mentioned you are "happy to pay someone to help". Feel free to reach out to me on Discord (luceos#0001) or check out the company I founded that provides Flarum related services as I think we would be a great match: https://blomstra.net.
(sorry about this wall of text 🙈 )
