Hotspot Shield gave me a bunch of malware and crap when I downloaded it, including the paid version, so I'm a bit wary of that. Just fyi.
I've heard that logging in and out on IPs that are say, from different countries or states, and doing it constantly CAN get you in frozen for suspicious activity or other things. I would say it's best to at least try to stay in the same general location with your ip.
I'm not sure to be honest, I would think it would be okay because some people do have dynamic IPs that change, but they are usually from the same company. I've been trying to find a VPN forever that will let you re-use the same IP rather than switching it every session, but I haven't found a good one yet that does that.