Questions about engine possibilities

[Jinix]

I know what you want to make - you have my same thought.
No war, no killing and probably no weapons? My favorite games have always been the 'discovery' type; chests, secret doors, well hidden quest objects that are really well hidden and a challenge to find and puzzles like the ones in this game Amnesia
You may want to try a more sophisticated game engine as in GECK or TESCS that Fallout3/Oblivion/Civ4 and a few others use.
These give you everything you need to create really large worlds and tons of ready made items to place in it.
With a couple of free (Blender and Nifskope) programs or expensive ones like 3Dmax, you can easily import your own models or just re-texture the standard models for a new look.
You also have grass and trees that blow in the wind, night and day cycles, plus NPCs with cool AI.

I've spent 1000s of hours making my own stuff with TESCS. I have yet to make a weapon or armor but I have about 200 NPCs doing things night and day in my world and it's a lot of fun watching them go about their everyday lives.
They go to bed, get up, have breakfast, go to work, break for lunch, back to work, go for evening meals at the pub , have a few drinks, get into fights, and go home to bed. On weekends they can have different routines that may include church, lunch on the patio, a walk in the country, a swim in the lake or maybe just sit in the town square and chat.