Warpriest Sacred Weapon and Humble Beginnings

[Codanous]

I am looking to make a Warpriest of Cayden Cailean and was looking at using the Sacred Weapon of a War priest with a mug and here's why I think I can;

Sacred Weapon:

Weapons wielded by a warpriest are charged with the power of his faith. In addition to the favored weapon of his deity, the warpriest can designate a weapon as a sacred weapon by selecting that weapon with the Weapon Focus feat (if he has multiple Weapon Focus feats, this ability applies to all of them). Whenever the warpriest is wielding a sacred weapon, he treats his warpriest level as his base attack bonus for attacks made with that weapon, stacking with any base attack bonus from other classes or racial Hit Dice.

The trait Humble Beginnings from Varisia, Birthplace of Legends which reads:

Humble Beginnings:

You didn’t have any intention of becoming an adventurer, but a single, unexpected confrontation changed everything. Choose one of the following: boot, bucket, frying pan, mug, rolling pin, spade, or stool. You are treated as having the Catch Off-Guard feat when wielding the chosen item. (These items should all be considered improvised melee weapons that deal 1d4 points of bludgeoning damage.)

The trait, doesn't give "Proficiency" per se but it does remove the penalty for it being an improvised weapon, does that allow the item to be open for feats like Weapon Focus.

Weapon Focus:

Choose one type of weapon. You can also choose unarmed strike or grapple (or ray, if you are a spellcaster) as your weapon for the purposes of this feat.
Prerequisites: Proficiency with selected weapon, base attack bonus +1.
Benefit: You gain a +1 bonus on all attack rolls you make using the selected weapon.
Special: You can gain this feat multiple times. Its effects do not stack. Each time you take the feat, it applies to a new type of weapon.
*Emphasis mine

Does having Catch-Off Guard for a certain weapon grant "Proficency" with that weapon thus opening up options to take feats like weapon focus or weapon specialization with that improvised weapon.

My rules question is: What counts as being proficient in a weapon and mechanically what is the effect for feats like Weapon Focus which require proficiency?

[MurphysParadox]

Try this thread which is really just a collection of links to other threads regarding the "Does Catch Off-Guard count as improvised weapon proficiency?" question.

The general idea is that no, technically there is no way to become proficient in an improvised weapon HOWEVER it is also perfectly reasonable for a GM to choose to interpret Catch Off-Guard as making one proficient in improvised weapon. Just remember that this is not a formal definition.

In a home game, I'd totally let you run this concept. In a PFS game, you are asking for some trouble if the table's GM disagrees with your interpretation.

[Codanous]

Thanks, I was looking around for something of the sort but was too focused on how it worked with Warpriests to just broaden my search to improvised weapons in general.