I think the solution to your issue is buried in the middle of that output:
npm ERR! Your cache folder contains root-owned files, due to a bug in
npm ERR! previous versions of npm which has since been addressed.
npm ERR! To permanently fix this problem, please run:
npm ERR! sudo chown -R 1000:1000 "/root/.npm"
After running that chown command, try running npm install again.