A few things...while not "cold" by any standards, nights have been cooler. Many Floridians, such as myself, have been wearing jeans/long pants and hoodies at night. Especially since the days have still been humid and in the upper 80s. Once you've lived here long enough, your cold tolerance goes waaaay down
The person in the video is a POI, not a suspect. They do walk like they know the area and are probably a local, making the same walk they do every night to get home. I do not believe they are the shooter.
Regarding anger at gentrification...yeah, Seminole Heights is experiencing some, but some areas have always been fancy and desirable real estate. It is an incredibly diverse area, but also pretty close-knit. For someone to be shooting people as a way to stop gentrification just seems...kind of like a plot for a bad movie.
Lastly, I don't think the shooter is on foot. All of the shootings take place a couple blocks from very busy roads. Both Nebraska and Hillsborough are main arterial roads, allowing anyone in a car to easily blend in with traffic.
I think this person just wants to shoot people. No political, religious, or social motive...just the thrill of taking a life. Which is honestly scarier than any of the aforementioned motives.