It is unclear who own the rights to my app/web design, will it be possible to download the code and host the webdesign on any server I choose or is it locked in with Adalo, the same for the Apps designed, will I be able to download the SDK?
Maybe Adalo is too powerful and capable for what you need- after all it’s not Adalo’s fault that you want to use it to do “something so simple”.
There are a number of cheaper- even free tools available to help you design simple web pages, or you could even just code every element of it yourself, assuming you know one of the scripting languages, and can then build the infrastructure to host it yourself.