Can multiple Templates Interact? And how would Dragonborn fit in with this?

[Neowulf]

pretty much what I've written above

I'm working on a multi-attacking swordsman, but I prefer Samurai to Ranger for the higher HD & better armor proficiencies

[OldTrees1]

Yes and no. Templates act like functions, a creature goes in and a new creature comes out. So multiple templates work like
Y=G(F(X)).

In other words, a template can interact with the results of another template, but not with the other template directly, and they are applied sequentially so only one interacts with the results of the other.

How do Dragonborn, Spellscale, and Hellbred fit into this? They are not technically templates, but act very like templates including their signature ability of interacting with the effects of prior templates(in these cases by removing those traits from the creature). The power of these 3 template-like races is in what they do not effect from the prior race + templates (with Dragonborn having the most & largest holes).

[Extra Anchovies]

Creatures can have multiple templates as long as they can all be legally applied. That mostly means that inherited templates have to be applied prior to acquired templates, and that any changes in creature type/subtype from one template have to be checked against the next template's requirements (e.g. an Effigy Half-Dragon is fine, but a Half-Dragon Effigy is not).

Dragonborn is an odd duck with its own little set of rules. Mechanically, I'm not sure how it interacts with true templates; the RAW seems to support Dragonborn wiping away most racial special abilities (from the base race, any inherited templates, and any templates acquired prior to the Rite of Rebirth), but I might be missing something in the template rules. Personally I think a sensible way to manage it would be to apply Dragonborn's effects to the base creature before adding any templates, even the inherited ones.