Just a minor correction: the 100$ one time deposit cannot be reclaimed manually. Instead, it gets automatically returned once your game hits 1000$ in sales.
https://partner.steamgames.com/doc/gettingstarted/appfee
The purpose of this fee is to block low effort automated scam games from misusing the shop.
Many successful indie devs have voiced that the 30% is actually impossible to beat for them if they tried other distribution approaches. Some even closed down their existing alternatives including self hosted shops which would grant them 100%, simply because the overhead costs ruin the percentage for them, plus a whole lot of time and effort that have to go into maintaining that.
Yes, steam has a very strong monopoly position on the games distribution market. That is problematic for all the usual reasons with monopolies. What makes steam unique is that the company behind it, Valve, has demonstrated in all their efforts that maximizing short term profits is not necessarily their prime directive. This can obviously change at any time, so being wary is always good, but convenience is simply extremely attractive to everyone involved, devs and customers alike.
They have different jobs. An officer receives and leads the mission and will bear the responsibility for how it's performed. A low level officer such as a 2lt usually deals with this on a small scale, such as a single squad. While this puts him close to the NCO's scope, the NCOs are focused on the inner workings of a squad or platoon. They can give valuable info on individual strengths for specific tasks in the squad and tactical familiarity. A good 2lt will use that and combine it with his higher level approach including logistical concerns ( timing, transport, supplies...), intel about the situation as well as comms with possible other active elements in the area to formulate a strong plan to maximize success chance and minimize risk.
A NCO has completely different training and knowledge from an officer. The whole planning and strategy part, including high level communication and logistics are usually of no immediate concern to an NCO. Still, depending on training and experience, they might have insights on particular fields, and a good officer uses any advantage.