It's great News

No, I am not using Instagram for e-commerce now, But it is possible and best strategy to share product and services on Instagram to become more famous.

Ahrefs and SEMrush are the best tools for Website analysis of competitors.

Thanks for this
It can't be seen as a spam when you have same content on different domain.

When we focus on generic keywords, then there is a difference between both of them. As you said that you were using ultra-specific to get your keyword at the top
In my opinion, For Everyone who are doing SEO for their website they must be ensure that always try to focus on long tail keyword instead of short tail to get ranked your website quickly.