We live quite near to Hurstpierpoint and DH commutes from the local area, so I have some idea.
As you probably know, you can either get the Southern train to Victoria or the Thameslink, which goes through London Bridge, City, Farringdon, st. pancras etc. DH does the latter route and, although he is very often delayed, he has always got to work/ home. The Brighton line does tend to still get a reasonable number of trains, even through current strikes.
Depending where you are in Hurst, the journey to the station is fairly simple,. From much of the village, it is walkable/ easily to cycle, but it's also usually fairly easy to park at Hassocks and Burgess Hill.
As for the village, it is lovely. I hear from friends that there is a really lovely sense of community and there always seems to be something on. It is also perfectly positioned to get out into the countryside, up onto the downs or down to the Coast and Brighton. If you are thinking of children in the future, the primary school is excellent and the secondary is consistently good too.