Can I delete all the posts and pages and just remake them like id want?
it's your own site, who's going to stop you?? Or are you alluding to the fact that you care about the rankings (as bad as they are) and you'd like to keep / improve them?
My question is, I do not like the look or structure of the site at all and think most articles on the site can be improved
where's the question? I'm not seeing it
Has anyone ever just deleted all their posts and pages and started over?
I have! And it hasn't turned out well for my sites in the beginning when I didn't know the importance of technical SEO and I ended up with dozens of 404 pages and broken links
You can delete everything and start over, sure! But you need to 301 each and every single URL of the deleted pages to another location or else your site will be full of 404s. And, of course, you can kiss the current rankings goodbye if you're going to delete the content that's currently ranking, even "in the 30 serps range" (whatever this means)
To be fully honest, your site is in good standing (it's aged, it's indexed, it ranks) with google, it just needs a few well placed backlinks and some content pruning and improving... and some internal linking too I assume, and you'd probably skyrocket it to the top within 1 month
Or how would someone go about doing that if that is what they wanted to do?
do WHAT exactly?? Come on, man, help us so we can help you!
You said that you want to keep the domain, this part is clear. But what exactly do you want to do with it? You want to delete everything (that'd be silly if you asked me) and restructure the entire site like you said? Or you want to improve it (like you also said)? These 2 options exclude each other and each one requires different steps, so which one is it that you want?