Salam.
That is a variety of issues that you feel is an implication within the Muslim society.
In terms of the issue of people not having manners , this shouldn't really be an issue because we should be the one with the best of characteristics , we learn from the qualities and characteristics of our beloved , prophet Muhammad (SAW). If one talks in a disrespectful tone , we simply remain silent and reply in a humble tone. How does one take out a fire ? By applying the opposite , water , in the same manner , we should not react in a disrespectful manner but the complete opposite , welcome the other person to peace.
As for people not giving Salam , that may be based upon the individuals , where I'm from , I smile to everyone and greet them with salon m vice versa , but this issue may be due to arrogance and in essence other Muslims thinking they're better than one another , but yes , we need to ensure that we are the first to give Salam, a warm welcome to our ummah.
I think a mutual issue you've mentioned is the issue of not wishing good upon others and jealousy becoming common in the society , we've become so brainwashed by the media that we simply are hungry for temporal desires/ objects that if we see others succeeding , instead of congratulating the, , we're becoming jealous of them, I know many who seem nice yet under their breath they wish negative upon their fellow Muslim brothers/sisters. I feel the society is becoming " A wolf in a sheeps clothing ", we need to sparkle the flame that was present before we were so diverted away from our deen and learn the fundamentals of our religions and try to act upon the actions and sayings of the prophet Muhammad " what you wish for yourself , you should love for your brother "( to the nearest meaning )
in terms of sisters sticking to cliques and small circles , is an issue for both , the brothers and sisters. However , this is not a grouped issue but merely individuals who have the element of thinking they're better than others hence not letting others associating with the, , I would recommend not trying to associate with them , if you've tried making effort and they won't take heed in what you're saying because we know that a person with an atom of arrogance will not even smell the scent of Jannah.
We live in a society where revealing sins has become the norm. Our own Muslim brothers and sisters indulging in such disgusting acts yet reveal it like it's perfectly normally , however , this does not mean that we should look at them differently but this should be a means of us reaching out to these individuals , alone , and tell them of the sin they're committing and his it goes against our religion , however to tackle this issue m we shouldn't just point fingers but try forming a bond before pointing fingers and it could lead to negative outcomes. Remember , stay peaceful and wish for others what you'd wish for yourself.
I think that's some of the issues I'll be covering for now , I'll cover the rest tomorrow unless someone else answers the, , if there are errors in my answers , please. Do correct me. I hope these answers have allowed you to solve your issues