I think early on when your site is new & has very little content and popularity, forced registrations don't work very well. The majority will simply leave without registering and never come back since there are loads of other forums to get the same stuff.
Make all sections open to guests initially. Work on building up permanent traffic, popularity and content. For a warez forum, content is king, remember that. When you have decent traffic flowing in daily, you can choose to make certain section closed to guests.
The logo looks fine, simple but effective. I don't see any need to change it. Skin looks good but perhaps a little generic but I am not one of those who would pay a hefty sum for a premium skin but that's just me :P