B0106-16272-BK Spring Back Door-Mounted Side Mirrors

Is the housing adjustable? The current angle to too shallow, needs to be turned towards vehicle.

No, the housing cannot be adjusted.
You can simply press around the edges of the mirror to adjust it to your desired angle.

Is installation on 1000&1000 XP models the same with Midsize models?

No, the installations are different. Please refer to the methods below.

Can the spring spot of the mirror be adjusted so they sit further back?

No, the spring structure cannot be adjusted arbitrarily. The angle adjustment could only achieve by pressing on the mirror glass.