See,it's all simple.
It can be done.
If weapons are the problem,make a dialogue where players can choose which weapons to use,if you really care all that much about people's feelings.
And what are the player ranks there for anyway,if we can't make something out of them?Just limit the security/president/vice to be chosen by players below certain rank and that's it.
Not saying you have to keep that score or above,but at least reach it once and you're eligible to choose security/president/vice from then on,since from then on you're supposed to have learned how to play on the server,the rules,duties and requirements,and then we won't have ignorant people and children taking on the important positions.For the terrorists,I think,it doesn't matter,especially since they have only one class.Those people will just shoot anyone in sight and that's it xD but if there were a terrorist class with armor right from spawn,to balance the existence of security,that would also require the limitations.