Technical explanation about text rendering is quite complicated.
To make it short, Android has to display a rendered and zoomed html page. In doing such operations it could happen that some fonts are not rendered perfectly as you can see on a desktop, especially if font is not included in Android operating system itself. Basically Android does not change any css property, but rendering could cause the side effect you noticed. That's why when text positioning is a critical, such as in a sticker book for example, I suggest you to: press enter and therefore force a new line inside the text box where needed; make the text box a bit taller and wider.
About readaloud, I cannot understand how double click during setup could solve your problem, but if so then ok. we will investigate about it.
About showing a blank page during page loading in Android and iOS app, it is a standard behaviour of our readers, it does not rely on project properties, therefore you cannot change it.
We are discussing about adding an option to change this standard behaviour so that user can decide if the reader app should load a preview or just blank during page loading.