Hi vtmoz
In my opinion, anchor text is not so important in these days, brand / domain / image / visit our website are good anchors. What it's really important is to have some of the links with the exact or similar anchor of the keywords you want to rank, and the rest of natural anchors.
About the page content or context content, the more related it is to the linked page, better. If the content relation is very low, it could still be a good link depending on the reputation of the linking website. The more reputation the linking site has, you need less content relation from it to be a "good" link.
Obviously, the link will be better where it has more content relation and the linking site has more reputation.
About the broken links you are planning to redirect, I would have to see the links, but unless they are backlinks from spammy sites, they should not harm your SEO. Maybe they just have little positive impact, but you don't have nothing to lose doing this.
Hope that helps, best wishes!

