What about if the attacking team scores a try from a play ball from within their own half it would be worth an extra point so not including kick returns or interceptions.

Why do we want to "open up" the game though?

There are plenty of points scored in SL, so defences clearly aren't on top and dominating games. Why make it easier for attacking sides by just exploiting fatigue?

How is that going to teach players to be more creative with the ball and make better decisions under pressure - both things we need IMO in order to compete with Australia and New Zealand?

Reducing the gap to 5m would significantly reduce fatigue in the defence. Also, it might well lead to more messing around at the tackle by defenders attempting to gain time for the line to space itself properly.

I think players are too fit nowadays for 5m to work. Line speed and modern defensive organisation would stifle creativity.

By "open tha game up" I mean introduce more variety to play. Less 5 drives and kick. Allow some rule changes to reward creativity and re-introduce some excitement that was lost when the battle for possession was downgraded. The way the game is played has become very strutured in recent years and can become very predictable.

I actually don't believe players are significantly fitter then they were in the mid eighties. Full time pros have a slight edge on their part time predecessors but I think the large number of interchanges allows average forwards to come on and gas it for 20. We are at a stage where skill has been superceded by the ability to get off the line quick and blow your lungs out for 20 minutes smashing the ball one up. Look at what Stevie Ward has slowly turned into. If you give defences the edge using the rules then I think you would force deeper attacking lines, better offloading in the middle in traffic from big men who could actually handle the ball and some actual thought and skill. A different type of player would become valuable and a kicking game would be an absolute priority - in danger of quoting Stevo, the short kick over a rapidly advancing defence would suddenly become an option. At the moment I could kick at SL level.
Attacking rugby is too safe, it's too easy to make metres and wait for a mistake from the opposition. You don't have to earn territory these days. If you watch entertaining games from the 70's and 80's you see the ball changes hands a lot more often as attacking players push and try things. There are more passes before contact - essential to open up a defence - but risky as every pass these days has to be justified. It might take a while - several years maybe - but a new generation of kids with hands, rather than body builders (the Burgess twins come to mind) would come through.

Never going to happen, but it would be interesting to see the experiment.

but as we saw in the internationals, it leeds to more wrong decisions. Or as it led to with the Hall incident, the VR spending ages looking at all the angles and still getting the wrong decision. Following the NRL seems a crazy idea when the NRL's officials are held in a pretty low regard.