Bismihi ta'ala

Although this is a very important topic, and it needs elaborate details, the initial thing incumbent upon you to do is to distant yourself away from such people as much as possible. 

Unfortunately, they are doing more harm to themselves than to anyone else, and they become a source of shame for all Muslims. 

We venerate our holy Imams (a.s.), and honour and respect them in the highest way possible. But expressions of divinity, like what you have given as examples, are exclusive to Allah ta'ala, and Him alone. 

They might be doing this innocently, under the pretense that this is a way of revering Imam Ali (a.s.), but if they themselves would have this during the time of Imam Ali (a.s.), he would have punished them then and there.

Our sources have mentioned these kind of cases, and they were condemned and cursed by the Imams (a.s.). 

Therefore, if you are able to discuss things with them, in a positive and constructive way, then that is good. If not, our duty is to disassociate ourselves from such people. 

With prayers for your success.