Other than when one's service plan data has been exhausted, at no time does HughesNet throttle anyone's service. Buffering can be caused by many things, with the most prominent being system congestion.
When you call it's likely that your system is "reset", clearing things out, which can have the effect of making the service better than it was for a while. If you don't already, you can unplug your modem once in a while and leave it off for at least a minute before plugging it back in. This can achieve at least some of what the reps do when you call.
As for your security camera, if you're speaking of WiFi signal strength, and it's inadequate for such, you may want to look at either the HughesNet WiFi booster, which can extend the range of the HT2000W's WiFi, or a 3rd party router that has better WiFi range than the HT2000W modem.
One thing to consider is that typically the transmitter in a home satellite setup will be low enough power that sufficient forward error correction is necessary. It's also typical that this kind of forward error correction requires a best of 4 redundancy. So although what you see is 3Mb upload speed, the actual data stream is approximately four times that. Bottom line: The low rate you're seeing is simply an engineering tradeoff to achieve an acceptible level of transmission reliability that's not necessarily required in the receive direction.