Possibly Stupid question imbue weapon+magic weapon

[VampByDay]

I'm not sure if this has been officially asked before or if it's been answered, google fu has failed me.

So, let's take the warpriest's ability in imbue weapons with which they have weapon focus with. Just for the sake of argument, let's say our warpriest is good with a light mace.

Now, At level 4 a warpriest can (for four rounds a day) increase the bonus on his light mace by +1, or can add a +1 equivilent weapon ability to his weapon from a list IF THE WEAPON IS ALREADY AT LEAST +1.

Here's the question, if I cast the spell magic weapon (or use an oil of magic weapon) on a normal (normally non-magical) light mace, then can I use the Warpriest ability to add a +1 ability bonus (say flaming?) I ask because magic weapon makes the weapon treat as magic and gives you the bonuses of a +1 weapon, but its wording is so confusing that I think it might not be allowed.

[Weirdo]

I believe it works.

I'm not certain enough to count on it for PFS.

[Gallant Armor]

It would work. The question would be what the enhancement bonus would be for the purposes of DR. For example, at level 8 if you add +2 to a weapon with imbue weapon and +2 from greater magic weapon, would it have an effective +2 or +3 for the purposes of overcoming DR?

I could see arguing it either way.

[Weirdo]

Since GMW isn't intended to help bypass DR other than magic, the reasonable ruling seems to be that you shouldn't count it when calculating what DR a weapon can bypass. So if you cast GMW on a non-magic weapon and then add +2 from imbue weapon, it would count as a +2 weapon for purposes of bypassing DR.