Maybe this is quiet brave suggestion, but longer i play i want it more.
I can say about myself that i am very experienced player but often disitinguishing if i am croutching or standing make me difficulties.
The same problem is when i am looking around. Often i have problems with recognize when i am in free looking mode and when not (i dont use TrackIR and make up for lack of this device with free look with a key).
Last thing is to recognize when i am in running mode and when i am in walking mode. When i doing small steps this is practically impossible to distinguish modes.
My propossition is not to show icon with soldier or something like in "Call of Duty", but at least dots that change colours under weapon description or something like this.