Does creating a Wonderous Architecture require a feat?

[Zhepna]

Hi,

I want to creat a Wonderous Architecture. Do I need the feat Craft Wondrous Item?

In the stronghold builder's guidebook, p.70 I can read:
Creating Wonderous Architecture.
To creat wondrous architecture (stationary or bulky versions of wondrous items)...

It's the only part they indirectly talk about a feat to creat those so I was wondering if I need a feat or not.

2)If I have a portable hole and creat a Wonderous Architecture inside it for it to be stationary, does it count for it to be stationary?

3) I cannot find a rule in the book to says immobile objects cost 25% of their cost. The following rules apply when not movable and it seems to only be 50% of reduction since everything is x 500 instead of x 1000

If the item is not movable at all—if it’s actually a part
of the stronghold and would be damaged or destroyed
if removed—then the cost is 500 gp × the spell level ×
the caster leve

[Telonius]

The listings of the architecture parts themselves list the prerequisites, in the very last line. I've done a quick scan and it looks like they all have Craft Wondrous as a prerequisite. (It's possible I may have missed one).

[Crake]

For number 3: 500 is 25% of the normal 2000 for wondrous items. 1000 is for bulky, which is 50% of 2000.

As for number 2: I dont think you could argue that, since theres no foundation that you can build the architecture into.