Driving traffic to google AdSense may not give you any troubles. But the clicks are highly monitored by google server. It is better to keep your overall CTR below 10%.
if traffic is natural traffic , i.e comes from SE. or Social network site and the same , why be worry?
If you get the traffic from twitter account , it is not a spam. Because they are the people who are following your site. When ever you update the site, you will update in your twitter account. So they come to your site.
In my opinion if you get traffic form Twitter it can't be spam, because you get that traffic in usual way, people get interested in you and only that reason they follow you...
Depends very much on how the followers were acquired, if they are from mass follows un follows and are not related in any way to your website then I think it could be a problem. It will affect your ctr at the very least.
I get traffic from twitter every day. I autopost to twitter when a new post is released. People go to the new post because they follow us legitimately. See nothing wrong with that.