if I'm understanding you correctly, you're looking for a sort of pre-set song layout? so, the Blocks themselves would be blank (just named Intro/Verse/Chorus/etc.), and then drawn into the sequencer in pre-determined structures?
so, for example, opening the Pop Song template, you might end up with 4 bars of Verse, 2 bars of Chorus, 4 bars of Verse, 4 bars Chorus, 4 bars of Bridge, and 4 bars Chorus, or something like that? then you'd just have to go into each of the Blocks to add your stuff and fill out the song.
is that right?
if so, that's a really easy thing to accomplish already. just create a different Reason session for each genre you want, add the Blocks you need, structure them in the order you like in the sequencer, and save them as separate templates. then if you want your Pop structure, for example, load up that template, do a quick save as to give it a new file name (that way you can use the template file again), and away you go.
doing this should take less than 5 minutes or so for each template.
if you're just unsure of structures that are out there, just do a search for song structures and you'll find a wealth of information.