I completely agree with the amount of money invested, I have spent way to much, but that's how it goes with all toys.
As for the questions; this will be more laid back (not less safe) compared to the practical rifle events I've attended.
My group of people are used to slinging bbs at each other, so this is a bit of a transition.
We'll be using cheap Wal-Mart stopwatches, and our targets are sheet steel knock-downs.
I would like to score by shot placement, but I didn't want to have to paste targets after each run.
Another issue is some players are coming with guns setup for cqb games against people; their limited velocity might cause issues punching though the cardboard targets I've seen at real competitions. They'll have no issues tipping my targets over.
As to forums, almost all us-based airsoft forums are dead, as games and teams move to Facebook.
The most active that I'm on is IllinoisAirsoft.com, but it's pretty dead.
I think some of the UK or world based forums are pretty busy, but I'm not a member of any.