Hi Alexander,
I checked out your website and you are ranking for some keywords like 'vintage sliding door hardware' and 'exterior barn door hardware'.
I see that a lot of the anchor text on your links is 'reclaimed wood wall art' so I'm guessing that's what you want to be ranking for. I can see that this is quite a competitive keyword so the sites ranking on page 1 of Google are currently stronger than your website. From a quick look it also looks like your website isn't relevant enough for this keyword i.e. it doesn't really mention the keyword in the content, titles, H1 header etc.
You will also want to make your anchor text more natural (either using your brand name or url) as using the keyword you are targeting too much can be harmful to your rankings.
In answer to your first question, yes on-page optimisation is still very important as that is what makes your website relevant for the keywords you are targeting both in the eyes of Google and your users.
In answer to your second question, it's always good to post as often as you can on your blog but what's more important is the quality and again relevance of the content you produce. You should ask yourself is this providing value, offering a new insight or answering questions that my customers might have?
I hope this helps!
