Oh god. Where do I start.
1. Have adjustable weather, eg. Snow, rain, hail, etc.
2. Have multiple worlds to choose from to forge on. Also, make the worlds BIGGER. (forge world in reach is tiny)
3. Add vehicles like: pelican, phantom, elephant, hawks, wolverines, space banshees, sabres, no Scarab as it's huge and unfair, and importantly; KEEP BOTH HORNET AND FALCON.
4. Get a larger forging budget, along with larger quantities of forgeable items.
There, that should do it.