solver

Place the newel manually.
 
Or, use a Pony Wall. Use a solid railing wall below set to be tall enough so the wall cap shows for your bottom rail. Normal railing wall above with no bottom rail.

That's what I would do using Pro or Chief because I can control floor and ceiling framing easily. Probably do this with Architectural too, but you will need to manipulate various dimensions to get the look you want.
 
With Architectural, I would experiment with using a thick ceiling finish. To increase that wall height, increase the ceiling height in the rooms, then add that same amount to the Ceiling Finish.
 
And please delete your thread on ChiefTalk via Moderator Actions near the top of the page.
 
https://chieftalk.chiefarchitect.com/topic/41697-how-do-i-heighten-front-walls-on-top-floor-without-higher-internal-ceilings/
 

You can set your newels to a 0" width, then place them manually (choose from library).
 

 
 
To force a full newel against a wall, pull the railing back from the wall, draw a Room Divider wall perpendicular to the railing, then another Room Divider from it to the wall forming a T.
Select the perpendicular Room Divider and move it close to the wall -- maybe 1/16" away. Then drag the railing wall letting it snap to the perpendicular Room Divider.
 

Using the Foundation Wall tool, draw the footers on the foundation level.

Your porch wall is not aligned with the house wall.
 

 
 
Aligned
 
 

Because that's one of the many things the people at Chief decided to omit from Home Designer.
Chief has all the functionality you desire, and it's all easy and automatic.

How did you rotate your plan?
 
In general, you should use Edit Area when rotating a plan. Grab the rotate handle and spin it around, or use Transform/Replicate to rotate an exact amount.

How did you rotate your plan?
 
In general, you should use Edit Area when rotating a plan. Grab the rotate handle and spin it around, or use Transform/Replicate to rotate an exact amount.

How did you rotate your plan?
 
In general, you should use Edit Area when rotating a plan. Grab the rotate handle and spin it around, or use Transform/Replicate to rotate an exact amount.

Ceiling height controls wall height -- and it does not matter if you uncheck Flat Ceiling Over This Room.
 
Roofs build over rooms.
 
With Suite, focus on the roof first. Once it's correct, you can turn off Auto Rebuild Roofs and remove the now unneeded interior walls that may have been required to make the roof build.

The framing isn't invisible, it doesn't exist. You need to build wall framing.
 
And you might review your wall definition. You have the exterior surface material set to be a paver and marked as framing.
 

I copied your data above, added a description to the first line and the import seemed to work.

@wrcolclough
 
My estimate was a bit off. It has taken over 3 hours to upload.
 
https://youtu.be/cVoVB5cZeyM
 

Use a custom backsplash. Draw a rectangle over the windows -- the program will automatically make holes for the windows.

The program is full of "helpful" automation that will frustrate you as long as you are using it. One of the issues all users face is figuring out if it's them or the program.
Your idea is sound, and I tried a bunch of things that I expected to work, but none did because the program is smarter than I am.
 
Yes, adding a beam and piers needs to be done manually.
 
Also, the Home Designer website has a search that includes the forum, and is a good place to look for solutions.
 

 
 
 

Don't overthink things like this -- keep it simple.
 
https://youtu.be/3MxCDvz-RTQ
 
To fill in the arch, take a cross section from within the alcove looking out into the room. Click the wall to place a Custom Backsplash. Open it and change its material, and set the thickness to fill the space.
 

https://youtu.be/R-gakp3X2wM
 

Sloped Soffit.

I'm using manual dimensions in the video, but you can Auto Dimension first, then edit those dimensions to do what I show.
 
 

Architectural lacks that feature, and it does not have Layout like Pro.
 
There is no real need for an elevation to be scaled -- no one should be measuring it.

Hold Control (or Command) and click the lower section to select only it.
Open it and change the railing.

Then don't.
Click (left click) to select, only right click if you want the Context Menu.