Ukrainian independence and Russian empire are irreconcilable opposites. This fact predates western aid to Ukraine by three centuries. So, "poking the bear" as a reason for war is as much nonsense as blaming Lend Lease for Germany declaring war on America on December 11, 1941.

Many independent countries had outside help to attain or regain their independence:

The USA had French help in its revolution.

("So, if America can defeat Britain, why do they even need the French?")

The Greeks had British help to defeat the Ottomans. ("So, if the Greeks can defeat the Ottomans, why do they even need Britain?")

France vs the Kaiser's and Nazi Germany in 1917-18 and 1940-45. ("So, France can defeat Germany, why do they even need the Americans?")

Vietnam vs the French and the USA had Soviet and Chinese help.

So your first question is an irrelevant red herring.