Is there a way to export all the activity for the contacts (through API or otherwise?). The GDPR is coming soon and it seems to me like there is a whole bunch of data that I would not be able to port if I wanted to (page visits and their sources for example)
Just to make sure that we're on the same page, are you asking if HubSpot will be GDPR compliant with respect to the data that we collect on you specifically, as a user? I'm not really able to talk about specific aspects of GDPR since I'm not a lawyer, but I believe you'll find the information you're looking for in the HubSpot Privacy Policy. Check out 6. Opting Out and Unsubscribing:
I have studied that page and it only addresses what if my contacts want access to their data. What if I, as a user of HS and a EU citizen want to access to all my data that Hubspot has? eg. that Hubspot collected due to me having your tracking code on my website?