Escaria Forum

Except for the obvious advantages no.

Their effects to sight- and detection-radius are summed up.
So, at higher lvls it gets less expensive to build a new than upgrade the old one (thats the case with every building)

The blacksmith itself has no effects.
Just the same way a barrack is only for training troops, the blacksmith is only for upgrade them.

So, if you have two blacksmiths, you are able to upgrade two things at the same.
But thats all

And to answer your next question:
Upgrades doesnt depend on specific blacksmiths. Theyre depending on troops.
So, if you build a second blacksmith, you will find the same Upgrade-levels, like in your first one.