I ask myself that everyday… 
… no but we both have pretty good insight into all systems. Albeit @Fredrik is the “owner” of the building systems while I’ve developed most parts of the agent simulation, passengers, employees, vehicles, stuff like that… but we like to iterate over each others code, break stuff, move stuff, improve stuff. Code has a habit of getting better each time you rewrite it and I’d say that if you’d compare the ACEO code base from one year ago with now, we have about 90 percent new code. We don’t use a git repository for that reason, we have a bit of a different perspective on version management I’d say compared to other developers. We do backup the code but only use the backups for reference, it’s almost always better to throw old stuff away and rewrite something from scratch.
Checked the stats and we’re currently at 96721 lines over 381 classes. We have major controlling classes for the economy and environment systems, as well as MVC patterns for all agents.
We can basically add any type of business we’d like into the contract system. Building hangars and renting out space I’d say is a planned feature down the road.
We can, but that takes a lot more time and is a lot more difficult. We live 10 minutes from each other so the issue isn’t distance, the issue is that this May is an insane month in regards to time management (I’m graduating, writing master thesis, doing a project for a company and moving out of my apartment right now… ACEO still has priority though! :D) . Will have a lot more time on our hands when summer comes.