From what I understand, they're not really brand-able keywords - brand-able would be a word/phrase that someone could use to promote, describe, or maybe name their product... those keywords are a little too vague/general for that.
Mid-xx basically means that the appraiser believes your domain could get somewhere in between $10 and $99 from a reseller or an end-user. Those are opinions... you may get no offers, or you may have someone that would pay much more than that because it happens to be just the name they want. I've purchased domains one week and resold them the next week for 5-6x what I paid... however, some will increase in value the longer you hold onto them.
Read through the newbies section, I've learned a lot from just browsing the posts in this forum.
Also, unless it was just a forum typo, "intresting" is spelled incorrectly - it's "interesting".