What is the difference between umwerfen and umstoßen and umstürzen and umfallen and umkippen ?Feel free to just provide example sentences.

umwerfen: to knock down (both intentionally and unintentionally, mostly objects)
umstoßen: to push down, mostly an intentional use of force, but it can be used as "umwerfen" as well

umstürzen: either "to topple" (government/...), in which case it is transitive, or "to fall down", often in passive voice as "umgestürzt sein/werden", "to have been toppled/to have fallen (down)" (intransitive)

umfallen: to fall down, only intransitive

umkippen: transitive (haben); intransitive (sein), to tip (sth. over)

umwerfen/umstoßen can be used as synonym, as can umstürzen/umfallen/umkippen

If you look at the actual meaning of the single parts in each word, you will realize the difference (or rather, that there barely is one)

werfen: to throw, active process
stoßen: to push/shove, more forceful and often intentional in my opinion
stürzen: to plunge, to lunge ("sich [in + Akk.] stürzen"), to fall (often either "down", or "in a bad/hurtful manner")
fallen: to fall
kippen: to tip (sth. over)