I do not know what "just west of HRP area" means but I live and work in downtown St. Petersburg. I have been here for nearly 25 years, and while the city has changed TREMENDOUSLY and is a very vibrant place to live, work and play, as a mother I can honestly say I would never let my kids just "roam the streets" as you mentioned. Depending on how old your children are, there may be places you would be comfortable having them visit that would be fine. There are beautiful shops and restaurants along Beach Drive, there are parks and activities nearly every day of the week that they might find of interest, etc. but in all of of that, you would want to know where they were at all times. That's not a St. Petersburg thing. It's an our-world-today thing.