I'm not sure how much the airport facilities would affect a business travellers decision on whether to use the airport. In all the people I've spoken to, the primary factors have been lack of awareness, door-to-door travel times, flight times, or choice of destinations. Facilities at BRS haven't been mentioned as a significant disincentive. (And bear in mind most "Business Class" fliers and those of us with FF Status escape to the Cabot lounge, and survey the thronging crowds from above).
They could be better - they should be better. BRS should be allowed to invest in better facilities if they think there's a commercially viable case. The way to reduce flights is to dampen demand, not constrain supply.
On an Asian/Middle Eastern route. I think it's going to be a long shot to make a BRS-DXB/KUL/BKK work with a 330-type if CO are finding BRS-EWR hard on a 757-200. EWR is a hub for North America, with CO/UA/US/AC. DXB is pretty much an EK only affair.
Flying west has a perceptual benefit that you're not double-backing on yourself (as you would going to LHR, or transiting AMS/BRU/FRA). Flying east not so.
TATL flights tend to go in the morning, which makes for a grindingly early 06:00 flight to AMS/BRU/FRA or drive to LHR, compared with a relaxing 10:30 from BRS.
Going east, most flights leave around 22:00. For my money, I'd rather get a connector out of BRS at 17:00 and pick up at AMS/BRU/FRA than slog to London at 18:00 (!!). (Coming back works better too - a 06:00 arrival at FRA means a 10:00 arrival at BRS. An 06:00 arrival at LHR means arriving in BRS at 09:30 via a jam-packed M4/M32).