If there is one thing that will always help with immersion, it's gestures.
General talking gestures (movement of hands our front),
wave (steady hand up and the moving hand),
hands on head,
face palm,
laugh (hands on stomach or flailing,
Surprise (hand over mouth),
Cheering,
Point,
If you see some Arma communities they have generic military gestures which people try to use. I feel the abInsert other media ove are a must to not only keep the immersion factor, but general communication would flow better and provide better RP situations. I really hope you consider this suggestion if you haven't already so that we may have some great RP scenarios involving gestures.