Your ideas are things that have been suggested in the past and wasn't liked and in some cases strongly disapproved of for a number of reasons.
The way Simcountry is built many players preferred the "Top down" system compared to your "Bottom up". In your scenario Security members would have Veto power. This means you could have EVERY new player spam the leadership with non stop requests for cash aid, or requesting wars/investigations on players who are below level three, or various other nonsense requests. By the sheer rate of spam, mistakes are bound to happen. Plus you would need several people to veto 1 topic, they would need more time which is cumbersome, and overall it would be a giant mess. This is why players favored the current system because in most cases the security council members are semi or very experienced players. It was preferred because you still need someone to reach out to a member to request aid, the group still needs to vote, then you need planetary vote. The bottom up system was disliked because many felt it would over complicate the process.
The Military idea was STRONGLY disliked and I wouldn't be lying in saying it was despised. The main reason people didn't feel that allowing the security council to have the power was because of abuse. How many troops, is it free of cost, what kind of weapons and quality, what about conflicts of interest? These are questions that have to be asked and it could easily be abused to give another player a MASSIVE unfair advantage.
-----Some ideas that have been requested but never had big discussions are-----
At one point I suggested combining Forbidding Nuclear attacks, weapons, and facilities into "Forbidding Nuclear Activities". My thought was it covers all the topics under one umbrella. Should a country violate the ruling a message be sent out. County A has built a strategic bomb corporation or Country A has purchased 50 Nuclear missiles. In addition, a Level 1 boycott would automatically be activated for the country which prevents the country from buying only "Services".(this follows the boycotts rules).
One suggestion was to allow the Security council to offer Disaster aid. Its identical to Development Aid, but a country must have suffered from an earthquake or nuclear fallout within the last 60 game months and cannot have received aid within the last 120 months.
Another was that Enforcing peace treaties should always reference the main nation of a player(s). The idea was that you could Enforce a Peace treaty with Country A. If approved the leader country and all slaves would have all wars they are currently involved in be ended immediately.