solver

What part has you stumped? If you have a 2nd floor, make a room there with a short ceiling. Create another room inside that one with no roof and a tall ceiling.

I'd send the plan in to support. https://support.chiefarchitect.com/

Slowdowns are sometimes a result of a symbol, or several symbols. The symbols available within the program are optimized, but ones sourced elsewhere may not be. Unfortunately, Home Designer does not have the tools to identify the problem. Does it just "get better", or does it go back to normal? Your computer may also make a difference. If it meets but does not exceed the minimum requirements, you may see a slowdown.

You will need to direct questions like this to the people at Chief Architect.

Does this happen will all plans?

Already available in Pro.

Read about these options.

Export/Import, or copy the User Catalog file from one to the other.

Install them just like you did with Architectural.

You can help us by using a Vector View camera as it shows edge lines making things like ceiling planes easier to see.

Switch to Vector View and take a couple more screen captures. Vector View almost always works best for images to be posted here -- makes it much easier to see problems like this.

Not that I know of. When I create or import a symbol using Chief Premier, I can set some sizing options, but they are limited, Home Designer does not have that ability. Symbols stretch uniformly.

Since you have Pro, and this is such a simple roof, use manual roof planes. You can auto build, but manual is really easy.

Not in Home Designer. You could use a Custom Backsplash set to Cut Finish Layers, but you would need to place one for each wall, and the corners won't look correct. Use a Wall Covering to simulate a base with a different material

You can do it a floor at a time, or the entire plan with a single click.

Looks like you have lost Room Definition on the 2nd floor. Check all your walls -- clear the No Room Definition checkbox. Select the Wall tool, hold shift and marquee around the entire 2nd floor to select all the walls. Open and check the setting.

Spray the new material or color on to the siding, or change the material in the wall definition.

You have circled levels. Go to Tools>Layer Display Options You should see a Furniture layer you can turn off.

https://www.homedesignersoftware.com/products/product-chooser.html

Suite does not have Pony Walls. The videos almost always use Pro so they can show its features. Suite is quite limited in its features when compared to Pro. Generally, searching Help for keywords, in this case pony, won't find anything, so you can assume it's a tool or feature you do not have.

Check these settings.

The default is to see all wall layers. Have you changed something? Maybe post an image showing the problem.

I looked and did not see a way to control it. I've never even been able to get a birds mouth at the top. You could try increasing the sub fascia. That's what controls the soffit.