Are we allowed to use textures, sound effects etc. from the starter content and/or from all the sample projects in a non-unreal engine 4-project with the standard subscription plan?
yeah in UE4 projects it is allowed, but in non-UE4-projects?
I think the ‘5% revenue to Epic’ model will apply if you use any content from Unreal Engine. It is that way for source code, not sure about art.
Evans is correct; sample content is part of the Licensed Technology so the royalty applies, even if used outside of the engine.
Can the content be used for commercial use? Items such as materials and blueprints they set up in free custom content to show off engine would be nice to use. Must we create all content for the engine to produce a game for commercial use?
Yes, it can be included in your commercial use of the engine.