Yeah, Merkel is to blame partially. She was the one who approved the 2nd pipeline. However, she didn't drive Ukraine into war. It's only Russia that started a war in Ukraine; no one else is at fault as much as them.
As for the migrant crisis... First of all, I admire Merkel's bravery for saying "fuck it" and accepting so many refugees in 2015. She allowed people to seek refuge in Germany, and that's great. Secondly, Ukrainians aren't different from any other refugees, and they are also fleeing to Germany right now. Who said white Europeans are better or more important than non-white Syrians? I'm glad Germany accepted Syrians back then, and I'm equally happy they aren't turning away Ukrainians right now.
I've been to Germany almost a dozen times starting from 2005 or so, and the last time I came over in 2019. I loved it both times. I hope you're not implying that seeing more non-white people is a bad thing. I'm from Toronto, Canada, and trust me: Germany isn't as multicultural compared to Canada.