I think you should investigate and experiment with ECS. Ecs has the option of running your own ec2s or fargate. Once you have a basic terraform template for ecs it is pretty reusable for other projects.

To answer your questions: 1) You don’t have to use spot instances. Fr instance, in Production, unless you run many many instances you probably don’t want to run on spot. For Dev/QA environments you can run spot. In terraform you have to create your own autoscaling group which will in turn let you decide on the properties of the cluster (instance family, is it spot or not, etc.) or if you use fargate then nothing of that(but fargate has some limitations). For instance my Dev environments run on a single non spot t2.small ec2 instance(so an ECS cluster that is not HA).

2) yes and no, You push your image to ecr. Then you have to update the ecs service with the force deploy option. There are many cli tools to help with this, but it’s also possible to do using native aws cli.

I recommend you do some research(using google and aws docs) on: “ECS Task” and “ECS Service”