Come to the conclusion after years and years of living in the area BOH is purely a bucket and spade Airport. Air Lingus didn't really help themselves by having poorly timed flights for business users..and Flybe have it sorted from SOU.
Think the holiday destinations could expand more in the future with with reduction of such flights from SOU..but can never really see more than that for BOH. Possibly a Polish route again at some point as no competition from SOU..but again Wizzair and FR tried and failed.
Rubbish transport links will always hold it back I fear..