On the second point, so many of the frames designed for street and DJ are singlespeed specific (Less shit to break right!). Meaning that with the correct hub they can be used either fixed of SS.
DMR have 'swopouts' (and i'm sure other dirt/street frame manufacturers have replaceable drop-outs too) so you can run either vert or horizontal drop-outs giving the added bonus of replace-ability if you break an end. Haven't seen a trick frame with this feature yet.
DMR have 'swopouts' (and i'm sure other dirt/street frame manufacturers have replaceable drop-outs too) so you can run either vert or horizontal drop-outs giving the added bonus of replace-ability if you break an end. Haven't seen a trick frame with this feature yet.