The thing is that most of the Steemians don't have power, so they can show their appreciations through comments because it may worth more

Wow. I never thought of it that way. This is so true. Anyone can throw around a few cents here and there but someone who actually reads your post and provides thoughtful comments is definitely worth a lot more.

I know that my thumbnails can be improved

I also have been thinking about working on signatures, thumbnails, banners like you have, etc. Thanks for pointing this out!

Don't bother too much with what people think of your posts; they are good enough, keep on creating. ;)

Haha will do! ;)