If you are removing Lava as a Viable light source, then you need to make torches at least 1 block more then what they are. I have put torches completely around my pumpkin patch and it never grew a pumpkin after a couple of hours in game. Yes I used Bonemeal on the seed til it was mature. I plan on re-opening my test world again and letting it set for a few more hours to see if it will grow, but if I waited 2 hours and the pumpkin never grew, then that means getting four will take forever and makes it almost a useless way to make a better light source, much less I would have to wait several days just to complete the quest that requires 4 of them. The only other light source requires a LONG walk to the CM that has the Nether in it, with I believe like 4 glowstone in it. I understand wanting to make the pack tough, but with almost no way of early light besides the Lava, then it would be pretty much impossible to grow a Viable farm to make food, or be able to grow enough trees in hopes of getting enough apples to make juice with. Maybe you could come up with another light source type that requires a little work but still possible early game? something between a torch and Jack'O'Lantern? For an Idea, how about a Stone Torch, that requires 1 stone stick and like 8 Luminite dust? an it would light the block its on and all blocks connected to the block its on. Im just tossing out an idea, but please think about it at least.
(Edit: when I said a couple of hours in game, I didnt mean IN GAME HOURS, I mean I was in game and left it while doing other stuff and 2 hours later I still didnt have a pumpkin, and yes there are just plain untilled dirt blocks around it for the pumpkin to grow on.)