The image linking shouldn't be a problem since you are unable to obtain link karma.
Well, sort of. Your hubwheel does fill up slowly. Actually there used to be a "clout" system where you gained clout both by voting on other people's posts and by having others vote on your own. The amount of "karma" you had determined how many votes you could make - for example, if you had seven karma, you could only vote up seven posts or comments in one day. Karma was itself tied to clout, so the more clout you had, the more karma you got every day. I believe mk made it semi-invisible and introduced the hubwheel to dissuade the devotion to karma-whoring that one sees on Reddit. So there's a wee Hubski history lesson! Oh, and you earn a badge every time your hubwheel is completed, which you can then award to a special post, and it'll appear forevermore in the badges page.