Thank you for a reply emoplato.
Well, then next question. Assuming a warforged uses Alter Self spell to change into a Warforged Charger,
1) How should Warforged feats interact with the new Warforged Charger Form?
Say, feats such as Adamantine Body, Jaws of Death, etc.
Should those feats applied when changed into a Warforged Charger?
One of the specific issue is about the AC of Warforged Charger. According to MM3, Warforged Charger is gaining it's Armor Bonus to AC from it's Adamantine Body feat, which usual Warforged Charger gains as a bonus feat.
Usually, when using Alter Self, a character does not gain feats which a monster usually has. And usually, the caster retains his selection of feats and can use them unless the new form cannot use those feats physically.
What happens if the said Warforged mage has Adamantine Body, Mithral Body, or non of such feats? Should he automatically gain Adamantine Body feat when changing into Warforged Charger? Or should the mage's feat selection applied (say, he will become a Warforged Charger with Mithral Body). Or, should such feats are all ignored and he will become a Warforged Chargere without such feats (ie, Armor bonus of 3)?
And, should other Warforged feats, such as Jaws of Death, Silver Tracery, etc., be carried over when changing into Warforged Charger?
2) How should Warforged components interact with the new Warforged Charger Form?
I guess Warforged Charger can use large-sized version of Warforged component items, and thus those items should be carried over (and becomes large-sized version). But I am not sure.