Question 1: What do you think of the overall design?
I like the basics of it, but it could use a little touch up. Just to use one example: Directly below the "The Blog" area, there's this huge blue wall of color. I think (?) this is a featured post from your blog. However, when I first looked at it, I couldn't figure out what in the world it was. Featured images are cool, don't get me wrong, but this one doesn't look very good directly on your homepage. When you add a featured image, make sure that it covers what you're posting about. Example: If you're posting about Ed Sheeran's new album,
Divide, use an image of Ed Sheeran, or something that resembles music.
Question 2: What do you think to the layout/navigation?
There aren't really any issues with it, in all honesty. It's simple, quick, and looks pretty good on mobile. The main thing I'd try to improve is the navigation pop-out in the top right. It looks great on my laptop, but it almost opens a new page whenever I click it on mobile. Instead of having the huge navigation link, have you thought about making it as a drop down menu, similar to what FP has? That would allow quick, easy access to whatever a user would like to find, but would also eliminate the annoying page that you're using currently.
Question 3: What is your opinion on the general site content and variety?
It's decent. The blog posts themselves are very good, your grammar is solid, the posts are reasonably long, and the topics are pretty easy to relate to. The big thing that I'd like to give you props on is the comment activity. Most blogs don't have that many comments (see: FP's blog), but you've done an awesome job of relating to your audience. You're also doing a good job of replying to users after they comment. This may seem like a small thing, but showing users that you care about their input is a huge deal. It'll ensure that users understand how much you appreciate them.
As a tip to improve - try to make two blog posts per week, if not three. I see some weeks that you made two per week and others that you only made one. You seem to have a few regular readers, and it could help them come back more if you wrote more for them to read. This isn't a huge deal, but it's a goal that you can work towards.