1. Can you use a shield to fight as if you were using a conventional weapon such as swords, axes, hammers, ect

2. If so, can you... dual wield shields???

3. If 2 is also true, can you dual block if you can dual wield shields???

4. if 1 is true, can you benefit from one handed perks?

5. if 2 is true, can you benefit from dual wielding perks?

No to everything.

Only 1 is true if you get the power bash (and hopefully deadly bash) perks, but even then it's not conventional (and it will likely be a terrible end-game damage dealer). Rest are false.

If you equip a shield, and then try to equip another, it will replace the first one you equipped.

Dual wielding shields would be most amusing however, and the icing on the cake of an already stupid combat system.

Shield bash is a interrupt, for example use it on mages that are powering spells.

I think the rest is false.

The rest is false
it is an interrupt AND a stagger effect