I'm not convinced that use cases determine Google's acceptance of how the service is used.
e.g. If someone uses the service to download & upload 100gb+ of data a day, and somehow it's actually for personal use, I suspect that Google would restrict them.
If so, the spirit of the terms isn't as much to delineate between types of use as much as it is to delineate between amounts of use.
Well, let's yell at Google when they do that. As it is written it seems go out of the way to address use case. If they just wanted to just go after heavy users indiscriminately, they wouldn't take care to say that they won't ban typical home use that would fall under the vague definition of server.
100gb a day is ~1% of a 1GB connection and probably completely ok with them. My guess is if your serving up multiple tb of upstream bandwidth they might have an issue but I have yet to hear of anyone doing so.
e.g. If someone uses the service to download & upload 100gb+ of data a day, and somehow it's actually for personal use, I suspect that Google would restrict them.
If so, the spirit of the terms isn't as much to delineate between types of use as much as it is to delineate between amounts of use.