If i have smithing skill at 100 but my level is still around 30, can i forge daedric armor?

You can forge daedric armour as soon as you get the daedric smithing perk. it doesn't matter what level you are.

If your smithing level is 100 at level 1 you could smith Daedric.

Yes.

Technically you'd have to be level 6 to get the necessary perks, right?

level 9, i think

Your level is irrelevant, only in-so far as it gives you the necessary amount of perks you may need. The minute you unlock Daedric smithing, then you are set. Assuming you have the materials.