It definitely sounds like an interesting idea.
On the side of Monopoly, one mode could have some resources/supplies be limited in some way, maybe with a little randomness in what players start with. So, while players will always have what they need to progress, they will have to either trade with other players or expand their own production to speed up progress.
Example. Player 1 trading some spare items that Player 2 needs to build up something faster, so Player 2 is willing to pay a bit more to get the additional resources, when Player 1 is actually trading for something they need fill a shortfall to accelerate their own progress to achieve the goal from another angle.
I would agree that direct conflict or anything relating to combat should be avoided.
I loved a game called Outpost, and the sequel Outpost 2 had a stupid combat aspect crowbarred in which basically ruined the whole feel that made the original game so good.
On the flip side, the basic premise sticks to mind. Of plans for a colony hitting a snag when a group decides to 'take' some of the supplies to go build a second colony, on the grounds that 2 colonies have a better chance for surviving than one.
It would be an interesting concept for a competitive mode of sorts, of enough materials to make a good sized, self sufficient colony, but having the resources split among 2 or more teams, the main goal being which team can achieve the kind of colony that was intended to be built in the first place.
To further the idea, each team gets the most basic of supplies (enough to survive but not thrive), with a main 'stockpile' (enough to build a good sized colony off the bat) that is broken down into an equal number of 'packages'. Then each team takes turns (order decided at random) selecting a supply packages (be it for farm stuff, mining equipment, extra rover fuel, extra medical supplies, etc) until all packages are taken. For added randomness, some key items (like rovers), don't appear until certain (random) things are taken from the stockpile (akin to some stuff being stuffed in the back of a storage room and not initially visible until other stuff is moved out), so people can't just get the good stuff and get a major advantage just by having first choice.
On the competition side of things, one side thing could involve rover races.
Or an Easter Egg Hunt type start. The basis, the teams need to produce X amount of items, however, the basics needed were on a lander that broke up when it 'landed hard' scattering supplies over an area, so teams need to sort through random bits of debris to find intact containers that have the needed elements, supplies and parts, and even usable bits of scrap that could be 'recycled' at a later date. Again, each team has the basics off the bat. While lucky players could get extra supplies off the start, another team with better management and more motivation could still make a comeback despite the first team having an early lead, while a third team could get a foothold by having a solid plan to recycle scrap debris others chose to ignore, allowing a short tern alternative to mining for some resources.