What is the basic difference between shia's and sunnis?

so as a question .. shia do not slander hazrat Umar RA and Hazrat Ameer Muaawiya RA keeping in mind he was Kaatib e wahi ..and do shia not consider Hazrat Umar a True sahabi…and why do the shia not also show the true status of Hazrat Hassan RA brother of Imam hussain ..the way shia show status of Imam Hussain .. Is it becos Hazrat Hassan made a pact between Hazrat Ali and Ameer Muaawiya …*know that the hadith of the Prophet SAW that which ever star sahabi you follw will be on my path .. ???

So many objections shia raise and make .. and what on earth is this .. that Hazrat Jibraeel mistakenly went to Our Prophet SAW at time of wahi ..whereas shud av been Hazrat Ali RA .. this is objection against Allah Almighty .. that he sent Jibraeel AS to wrong person .. yet Allah told that Angels do not make mistakes ..

Shia in my point of view and in my belief infact are most controversial group out the lot..

^^ these are just some most talked about / discussed issues against the shia amongst many ..and if someone dosnt consider these objections as hate/slander towards sahaba then …I suggest that that person study from scholars.