I watched it few days ago and I'm pretty OK with it. Granted, I don't expect much from a "come and see us" video. Or maybe it helped that the last video a Brit did in Sofia that I watched was about gypsy thieves and clans and featured shots of the Sofia centre under rather Turkish music. 
It's not TV but still, without the cliches I don't think it woul've gotten made or that popular. And the "you can see it in one hour" I take as a regular sales pitch, having nothing to do with the truth and saying  it won't take too much of your oh-so-valuable time. 
"Hasn't grown old" is indeed a reference to the city motto.
And I don't get it - what's wrong with Constantine loving Serdica? He kinda did, and not just in words. More than our current government does, anyway :P

I think the idea of you doing a video log is quite good. Wether it's of your travels around the country or abroad or just in Sofia. Next time you walk around and notice or think of something that you'd want to write in your blog, take out your camera and tell it to lens :)