I've been contemplating on the best way to set up a dragon slayer RP character. I want to try to remain reasonable as possible.

Race: ??
Shout: ?? (Possibly Fire Breathe, just as a kind of gimmick?)
Weapon: 2x Steel Sword (Upgrade to Ebony Sword at level 36) One with damage fire one with damage frost
Shield: Imperial Shield (Upgrade to Ebony at level 32) Resist Fire
Armour: Full Steel Armour (Upgrade to Ebony at level 32) Resist Frost boots
Jewelry: Resist Fire amulet and Resist Frost ring

Perk set:
http://skyrimcalculator.com/#139829
What else would you remove/add to that to better help the build?


Questions:
1. Is dragon breathe considered magic? If so, should I put Resist Magicka on my items?
2. Is power bashing realistic at all? If so, should I use it?
3. Am I OPing my swords by adding the decapitation perk?
4. Should I eventually upgrade to daedric swords and armour? I don't find anything that isn't Ebony or Steel to be even close to realistic, although I would feel like a bad ass slaying dragons in Daedric I don't feel as if it would keep the RP feel.
5. Should I poison my blades?
6. Is it possible to put fire and frost damage on one sword with the Extra Effect enchantment perk?
7. If Dragon fire is not magicka, is it possible to put resist fire and frost on one piece of armour?

Spellbreaker would fix all your problems.
Dragonbane sword instead of ebony use full blades armor, or whatever.

Dragons shouting is considered Magicka

No I meant when a dragon shoots it's breathe at me, sorry for the confusion.

Spell breaker doesn't seem very RP like in my opinion. I know what armour I would like to use, I am just wondering as to whether or not people feel like Daedric armour does not fit a dragon slayer's RP theme.

Dragonbane seems like a good blade to use when I am in my upper level 40's (I want to obtain it when it is at its max damage rating). Thanks for the protip