Axes Equip
 

Yes well, in real life people couldnt use a shield with an axe... they had to use 2 hands since it were so heavy but very strong, shouldnt it be , you cant equip axe if you have a shield on, lets say if you have axe equipped but no shield, in your inventory will be your shield if you have axe equipped the shield will bed glowing red meaning its unequipable if you have that weapon type wielded... and also for archers too no shield..

You'd be able to use a buckler, probably, but that's about it.

Vicious Axe weighs bout 4.5 kg's more than a Diamond Blade.

That's a bit off, but you can use Axes as one handed weapons. Depends on the size of it. Since the axes seem to be only a little bit larger than a sword, it shouldn't be a huge problem.

..
 

they should make Hand Axe a bit weaker but fast and can be equipped with shield but big axes are strong / no shield they'll make it a bit stronger like +10 dmg?

i think axes should use both hands and be really strong, besides when you swing you use both hands anyways but your shield disapears x.x