I have been a Hughes user for nearly 13 years. In that time I have went from a daily allowance of 250 MB to my current monthly 50/50 GB.
In all honesty, there is no way that anyone can use a data capped service to be the functional equivalent of an uncapped ground based ISP.
There are a Boat Load of things you can do to cut needless data usage ... and it does help ... big time, but not enough to make a data capped service into a ground based service.
Satellite Internet is intended to serve a niche market ... namely those that have no other option other than perhaps dial-up. It does not, can not compare or compete with ground based Cable, DSL, FIOS or even cellular or WISP services.
I look at it as a lot like being poor, you can look at all the pretty stuff in the windows, but you need to check how many pennies you have in your pocket before you decide to "buy" a file download, stream a movie or music service.... You have to keep and eye on the "fuel gage" and prioritize what you wish to "buy".
I'm betting you are wasting a good portion of your data in ways you are not aware of. Making a number of changes will extend what data you have to use on things you really want can really help but no, you will not be able to use your capped service for "cutting the cable cord" activity.
Video activity is THE most data intensive thing you can do. You can reduce playback resolution and that will help but it is no real replacement for unlimited ground base service.
My advice, Get Directv (or Dish) and use that for TV. Just don't hook it to your Hughes system.
Change is coming ... but a $600 million dollar satellite with a finite data throughput and a 12 to 15 year lifespan does not equal ground base ISP service.
We can help you save useless data usage but we can't make your Hughesnet connection the same as Cable.