@fffddd-dfeeedd No, most likely they will not affect Google rankings. Any external links from NodeBB are automatically nofollow'd, and those bugs you've pointed out don't affect ranking of the page itself.
@fffddd-dfeeedd Not much. Many potential confounding variables. From my experience, I would posit that it is not googlebot, as the periodicity is too irregular. I (used) to see big spikes like that from the goog, but they'd tend to be spaced at multiples of four or six hours, depending on how busy my forums were.
Do you have access to your webserver logs, e.g. /var/log/nginx/access.log ? If so, look at those times and see if you can correlate w/any particular or small group of IP addresses. Then reverse lookup those puppies and see who owns them. Otherwise we're just grasping at straws.