A few changes that could help heimy:
-remove gold earned when u kill his turrets.12g per turret is just easy money. That's like having an extra minion every 2 waves, money cow for the ennemies !
-increase grenade's speed / blind duration.
-reduce mana costs.
-Make his rockets and turrets focus blind people. If there are more targets blind than there are rockets, it will hit the closest blind target.Somehow like urgot, you see what I mean ^^'.
-his ulti: instead of healing turret, it could make them invincible. Like tryn's ulti, but for his turrets.