Stat Generation depends what you want to focus in. It's fairly common to only go 4 levels into DD for that extra +4 STR, and if doing so you probably want to focus on STR more than anything else. Stats probably look something like: STR > CHA=CON > INT=WIS=DEX. The Paladin dip is worth it if you need higher saves, I'd say if you have 16 CHA it's almost always going to be worth it, 14 sometimes worth it, 12 or less it's not worth it. 2 Levels of Paladin also gets you 1/day smite (not much damage but +CHA to hit/AC and ignore DR) and a little self healing from LoH (or you could go Oath of the People's Council Paladin and swap Smite for bardic Performance - my new favourite). This really depends what you're losing for it - for example taking 2 levels of Paladin means you push your DD levels back 1 because you won't get your Bloodrager spells till character level 6.
I'm not sure that taking levels of monk helps with natural attacks, you should look up Natural Attacks because they work differently to everything else. I did see a DD build that used Bloodrager and 1 level of SCALED FIST monk to get CHA to AC that worked pretty well.
You don't want to delay your chosen spellcasting class any more than possible.
Two levels of Paladin, tops. Get charisma to saves, it's all you need from that.
The Magical Knack trait gives your caster levels back that would be lost with the Paladin dip. You still lose one CL going into Dragon Disciple, but oh well.
Might look into Eldritch Heritage feats for Orc Blooded. It grants you more bonuses to strength and the ability to grow to size large. Meeting the CHA prerequisites shouldn't be difficult for a Bloodrager.
You don't want to delay your chosen spellcasting class any more than possible.
Two levels of Paladin, tops. Get charisma to saves, it's all you need from that.
The Magical Knack trait gives your caster levels back that would be lost with the Paladin dip. You still lose one CL going into Dragon Disciple, but oh well.
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The Favored Prestige Class and Prestigious Spellcaster feat chain can help with that. Keeping full spellcasting progression is really nice and the extra hit points or skill ranks are also nice.
So should I ignore scaled monk and just go heavy armor?
I would say yes. Skip the monk and wear heavy armor. Dragon Disciple is usually focused on strength, so I doubt that you will have enough dexterity to run around without armor, even if you were adding your charisma to your AC along with your Dex modifier via dip in Scales Fist.
For whatever reason I just couldn't remember the name of the Prestigious Spellcaster feat, but it's pretty much essential for most prestige classes.