I would say it is simply technique although pushing the rear wheel forward would naturally help. Next time im home, have a go of my bike, its a little lighter at the front than yours, but it will give you an idea of your bike with a shorter wheelbase.
I can help you take a link out of your chain if you still wanted as it only takes 5 minutes and push your wheel forwards; you wont necessarily require a chain tensioner - i dont, and we have similar bikes.
You have the skate park local, so just keep trying using the bottom of the shallow inclines to help lift the front. If you cover your rear brake you wont come off the back of the bike, and even if you do, its a case of putting your feet down.