Two of these seem to have do-follow links for their comment links.
1: Are these links just as good as "guest post" links in terms of SEO? Does Google differentiate between links in comment sections and links in main content areas?
2. Can these be overused to the extent that it would get my site penalized by Google? How many would be too many? 5? 10? 200?
3. Obviously anything that gets my pages in front of readers is good, but from an SEO perspective, are links in comment sections for the time/effort?