I am playing Dota for almost 10 years and usually floating around 1.2- 2.2. . I 've seen lots of different metas and I know that almost all heroes may be played at any roles. Howewer, I believe that is valid for much higher brackets and players since playing with the heroes out of his primary role brings the complexity and uniqie experience for specific gameplays and match-ups.
For my bracket, things don't work as I write above. Players that picked heroes that don't play as his primary role are mostly showing us classic build and play of their heroes. It frequently ends up with chaos and rarely ends up in a good way.
My solution is hero striction according to roles at the picking phase depends on the mmr bracket. as MMR increases, heroes might be viable according to picking rate of the hero on related position.
For shorttakers, I would like to see an end for era of the pos 5 pudge and Invokers or pos 3 carry's. Someone have to do something about it.