Europe can police their own back yard. If they aren't capable, we've wasted untold trillions and years creating a Euroweenie welfare state.
No, and no.
And, it's not even all about Russia (tho' the lean toward Russia increases if one considers Moscow part of Europe.) We KNOW from history what happens with Europe when well armed and left to its own devices. Post WW2 you can add in nukes, at any point had the US packed up and gone home. And if you don't recognize the divisions still in Europe, hidden to the ignorant by the thin veneer of the EU, and relative peace held together not just by trade, but by the glues of NATO and US influence, well... I can't help you. I don't know how to cure blindness.
Waste? Well, since the demise of the USSR, the Euro's haven't really contributed their full / designed share to NATO. But, their contribution is still helpful. And, together with a few other allies, the Western bloc is ~80% of the world's GDP. Europe's contribution there is larger than ours. Getting that block to move together is often difficult. Getting it to move together quickly can be VERY difficult. But, make no mistake, it is enormously economically beneficial (basically to all), and it is the most powerful human force on the planet.
When it comes to NATO, obviously some things need to be addressed. One is to address funding: The 2% of GDP requirement needs to be an absolute minimum requirement for Membership. So long as Russia is a threat, it likely needs to be 3%.