I would prefer to have few weapons, but have more content in other ways. Like multiple types of ammo for each range weapon and/or upgrades that can be done to the weapons/tools. Thus more stuff to collect materials for and craft...
To me, this game is mining, collecting, gardening, husbandry, dungeon crawling, exploring, crafting, building, survival, PVE and PVP with just a few FPS elements which are balanced so they don't take over the game (but hey.. maybe some people want this game to be hardcore PVP and the crafting/building are secondary, should be able to setup a server like that. Different game modes are a key to this games success IMO).
And I hope for some inventing. Part of MC was creating new stuff with redstone, Space Engineers lets you do that in a way also. I like the idea of, here's some parts, power sources, machines, tubing, pipes, wires etc.. figure out what you can do with them. Connect some shit together and see what it does... Even problem solving, like how to better harvest your pumpkins. Or how to collect water and store it in a tank for later use in the garden but you're 200 feet above the river or lake, got the stuff to make a pump and power it? Don't want a set recipe with specific parts to make this stuff. Let's take the pumping water idea. What if I use 1 inch piping at the water end, but beyond the pump it's 6 inch piping. Result will be very little pressure at all. But if I reversed it, running a 6 inch pipe into the pump but beyond is 1 inch pipe.. I might just destroy the pump but it'll have crazy pressure. Or I just keep it simple with good flow because I know it will be the main source of water for the garden and I want it to last. I would like to experiment like that. Interesting lighting displays, water features in the garden with underground piping.
Oh! You can currently place dirt right, what if you dug a trench, placed some piping down into it and placed dirt on top to cover the piping and level the ground again? Would that get crazy with the coding? haha It would be great. To fix it you would have to dig it up again (and we should have to do maintenance on things like powered systems. motors wear out... pipe connections slowly fail...). Anyways.. I can go on and on with ideas for this game lol
Regarding survival and teamwork. Well people will be playing with their friends... but others will want to be lone wolves, the game needs to accommodate both. So there should be group survival mechanics and stuff a single person can do to survive. With my above idea, it works. Groups can figure out ways to farm on a larger scale, and an individual can figure out his own stuff.
Last thing, using a torch or something similar to scare off a predator would be great. A flame torch could work during the day even, but other items might work just at night. I recall on the news one time this guy went up north and arrived at night. He was walking in town or something and got a polar bear after him. He only survived because he pulled out his cell phone and of course the screen lit up, when he turned it towards the bear it ran away. Would be good to have this kind of thing in the game as like a last resort. Also, a camp fire should keep predators away...