Google will not penalize you for removing links, although your rankings may drop if you remove links that are helping you rank.
But keep in mind that links that are helping you rank today, could end up causing a penalty tomorrow. If your links are spammy, Google will eventually catch up, it's just a question of when. To be safe, you should remove blatantly spammy links.
Keep in mind that there are hundreds of ranking signals. Just because Moz is reporting that your PA/DA is better than the competition does't mean you _should _be outranking them.
Some traits of bad links:
- The link's anchor text exactly matches your target keywords (eg. "Miami Auto Repair Shop")
- The link is on a website that is unrelated to yours and likely has little traffic/readership
- You paid to have the link placed
- You "submitted" an article to get the link posted
- You control the site that the link is on
- The link is in a link farm/directory (a site/page with a bunch of links that are intended only to impact SEO)
Hope this helps! I'm happy to give you my input on specific examples if you have them.