I am not sure which part of sitefinity azure support or documentation still refer to sitefinity 4.x version and please let me know so I can update this.
For a deployment I can recommend performing the Azure deployment with sitefinity thunder which is automated deployment following a wizard which performs all configuration changes needed for the site to be Azure application automatically, here
is the related documentation for Azure deployment.
The usage of cloud service or VM to host an Azure site is your preference depending on the project needs and estimated user visits in the site.
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items