Actually the field does initialize itself with a null value, but since OpenAccess doesn't support int?(nullable) type, it puts an int(regular) in the view-model and this is why when you republish the item, it gets the value from the view model and puts it in the database - if you check the database before you republish the item, you will see that the value is null.
As for the inconsistencies - this really seems a little confusing by design, so we will consider changing it for our future releases. Thanks for the suggestion.
All the best,
the Telerik team
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