solver

Do not use the Dormer tools, create the dormer manually. I have a couple of videos on my YouTube channel that might help.

Preferences and Defaults are different. Things like ceiling heights are set in Defaults. The default 1st floor ceiling height is 9'. Just add 1' to whatever is shown in defaults.

I used manual roof tools for this part of the roof. everything else you can do with Architectural. In your first image above, you had the roof in this shape, so maybe it can all be done without using the manual roof tools. With Pro, the roof would be easy because you have the tools.

What's correct for the ceiling -- 96"? And remember, you have manual roof tools in Pro. For a simple project like this where auto roofs don't behave, manual is quick and will give you what you want.

If you will attach the plan file -- close the program first, it will help someone troubleshoot.

Close Pro and attach the plan file.

Raise the roof or lower the ceiling.

Pro has all the tools you need.

Easier to troubleshoot with your plan file. Close Pro before you upload.

Yes

Since the house has a 2nd floor, it's best to create it now. Can you open the HDA 8 file in the 2021 version?

What is an "automatic overhang"? The slab should not change the countertop.

Not easily. You can use a Custom Countertop with a molding.

Those are CAD lines. You need to edit them (Stretch CAD etc) to create a new Arch D layout. Save As into the layout template folder for reuse, or if you want this as your default layout template, rename the existing default template and save the new one with the default name. I used Stretch CAD and Point to Point move to resize this in a minute or two.

That's because they are auto EXTERIOR dimensions. If you want Auto Interior Dimensions, you need to add that tool to your toolbar. This tool was removed from the default toolbar because it makes a mess with dimensions -- after you try it, you will see. Here is a thread with some info. You can also change this setting in your wall definition. And I would recommend drawing an entire structure (does not need to be accurate, just form an enclosure) even if only doing a kitchen or bath, for example. Put a roof on it and build a foundation. Lots of small things work best with a complete building.

You might try copy/paste (use Edit Area) from one plan to another.

See your dimension defaults. The links above might have some specific info.

It's the same. Follow the instructions to build the gable version, then drag the hip walls around to replace the gable end walls.