If you're making the effort to travel from where you live to S Wales why not enter and see it all? Yes, spectators are welcome.
I suppose you are right, but the wife might not be happy coming with and not doing anything! lol
My girlfriend rode pillion with me last year. She enjoyed it and it was a fun day. For the off-road (test) parts, using the Off Road Skills bikes she watched. It's a great, well organised event and certainly not a flat out race.