Is it bad for SEO to add too many tags for a blog post?

I would say that you run the risk of duplicate content penalties if the tags are links to pages showing the different posts related to the tag. However it is a great way to get your readers to interact with the site and deep link to different pages.

 

great discussion. all things are good in moderation. add a few tags (or a lot - if they're all relevant), go canoncial and nofollow your links. that's the best strategy i can tell you.