1. CI/CD pipeline can be implemented utilizing the same tools that you would use to deploy to K8s or any typical server. It will involve either zipping your code or building a container image. Regarding canary and blue/green deployments, it's all possible with API Gateway, have a look at https://docs.aws.amazon.com/apigateway/latest/developerguide/canary-release.html.
2. Great point! I'm releasing an article next week precisely about that! :D
3. Interesting, for me, it was always spun up immediately with my demand. Maybe you can write about that on https://www.reddit.com/r/aws/.
4. Try using Docker; this way, you can test locally: https://levelup.gitconnected.com/deploying-aws-lambda-with-docker-containers-i-gave-it-a-try-and-heres-my-review-147327519ce9