Hiver,
Any game played through 3 times will be very very easy. I doubt it that when you played game very first time it was very very easy for you. Thats the nature of all the video games. as more you play as more accustomed you become and as better you learn game's features.
The big problem here is if Larian listens to you and those like you who played game through 3-4 times and then adjust the game difficulty to your liking the game will pretty much become impossibly difficult for the rest of the players.
I played it through once on normal and no its not very very easy. It does become easier as higher level you become but this doesn't mean that game is very very easy. Game became much easier on higher levels and very easy in the end only because there was nothing else to fight on the map.
Questing in D:OS is pretty much a mess. So most of the people will end up just exploring and killing things and getting new loot and abilities with a few hardcore players trying to get every quest done too. So I believe with a bit of tuning and giving us ALL the promised content on release will balance things out a bit.
Understanding of challenge is different for different people. Thats why there are difficulty levels in game. But devs still have to balance the things around in game because when your team are level 7-8 you can pretty much kill anything on the map without any danger of losing any of the team members.
Thats why this Beta map I believe has bosses that can't be taken on until later levels. So things just need to get a bit balanced. But game is not very very easy unless of course you played it 3 times through and know it as good as back of your hand.