@afeauto:
1. I think you are confused with “Settings => Readings => For each article in a feed, show” Full text. This is for RSS Feed. For blog post to show full content in archive pages, you need to go to “Appearance => Customize => Theme Options => Layout Options” and in “Archive Content Layout” you need to select “Show Full Content” then save changes.
2. For Bad Request in Read More. Can you check your permalink setting at “Settings => Permalink”. Try loading default, save changes. If this work then there must be issue with permalink. Maybe try to add custom as /%category%/%postname%/
and leave category base and tab base empty.
3. You have added in logo, logo will always display in all pages. I think, you are confused with logo and header image. Yes, you can change the display option if you remove that logo and add image as header image. For Header image go to “Appearance => Customize => Header Image”. Here upload your image and then to show only in homepage you need to select “Homepage/Frontpage” from “Enable Featured Header Image on”