I've got a E2 Micro instance running on Google Compute Engine at the moment.
Although it won't be using bandwidth quickly (expecting a maximum of 600Mbps), it will probably be using a lot of bandwidth in total (expecting around 10TB a month)
Are there any limitations to how much bandwidth my VM can use in total per month, or am I only going to be limited by speed?
You will be limited by your credit limit. Review network pricing. Internet egress bandwidth is apx $0.12 to $0.23 per GB. 10,000 GB is $1,200 to $2,300 per month.
Search for "Internet egress rates" at this link:
Google Cloud networking pricing
Note: for new accounts, IIRC your payment method will be charged at $100.00. Double-check how your account is setup.
For example, if your Cloud Billing threshold is $100.00, and you have not yet incurred any costs for the month, you might see a message that says Your entire $100.00 payment threshold is available.
or
"You'll be charged when your balance reaches $1000.00 or 30 days after your last automatic payment, whichever comes first."
