I have a number of parked URLs made up of keywords relevant to my business domain, www.example.com. Would it help or hinder my rankings to have these parked urls directly link to www.example.com. With the exception of one of the parked URLs, I will most likely never actually have a live online webpage for these parked URLs.
This is a relatively common thing to do, espeically with potential type-in domain names, and the practice can pick up some traffic.
If these domains had no previous owners -- and while under your ownership there's been no activity either -- then you should see no impact on rankings whatsoever. The situation to be wary of would be a precious owner leaving a legacy of funny dark business. So before you take this kind of step, I'd say look into any history of the domain you can find in the Wayback Machine at archive.org.