if i convert warpath damage to fire using the node in its skill tree will increases to physical damage still add to the skills overall damage ?
No, as the node says, increases to physical damage won’t apply as you’re not doing physical any more, you’re doing fire. LE treats conversions in a more logical and less egregious way than PoE. Conversions happen once then % modifiers are applied (rather than apply % modifiers then convert then apply % modifiers then convert then apply % modifiers then convert then apply % modifiers, etc).