Neither the cell booster nor DirecTV box are likely to interfere with either the dish signal or wifi.
Even still, ethernet cable connections are still the best option for connecting devices (printer, computer) to the modem. Phones would still need to use wifi, but if you have a booster and can use LTE for them anyway I'm not sure I see the point of even bothering to hook them up to the modem at all.
While I'm at it, it's not recommended that you connect the DirecTV box to the modem at all, because they are notorious for eating data like there's no tomorrow.
* Disclaimer: I am a HughesNet customer and not a HughesNet employee. All of my comments are my own and do not necessarily represent HughesNet in any way.
