http://wiki.guildwars.com/wiki/Recharge
It's not explained explicitly, but to my knowing and experience, skills and weapons don't stack with these kind of effects. They do work seperately. Skills can't stack to bring more than a 50% recharge, individual skills that exceed the cap still have their effect.
In the case of MoR+HSR on an item, I think the MoR will effect the normal recharge, and that recharge will have a chance of halving. Don't quote me on it though, I might be wrong.
Edit: halved skill recharges can't make your skill recharge faster than 1 (one) second.