Your Comcast remote can probably be made to control everything, even in RF for minimal cost, as can other JP1 remotes like the RCA RCRP05BR ($13) plus Next Generation RF ($40).
If you want an inexpensive RF remote, check out the URC RFS200. If you have more to spend, Harmony's latest offerings the Ultimate and Smart Control are good options. If you have a lot more to spend, higher end URC, Crestron and RTI are also options.
IP control and smart phone / tablets are also good options if you don't mind touch screens (iRule, Roomie, etc.).
RF will only help with your interference issue if you place a blaster directly on the IR window of your DVR and not rely on the base itself.
I know nothing about Samsung Smart Hub, so I can't help you there. Suffice to say, if your Samsung remote is IR and does everything you need, then any universal remote can do everything as well.