Now days you don't need acrobat reader typically, Chrome, Edge and Firefox can all view/print PDF's. If your on a Mac/iOS the viewers are built as the OS uses display postscript internally (quartz) which matches up pretty closely with PDF.
Chrome/Firefox don't handle complex PDF's well. They render slowly and sometimes inaccurately
It's not uncommon to print things from Chrome/Firefox and have the margins/cropping be wrong. Then again you're using a web browser to print a pdf file, you get what you deserve
Firefox I think still uses https://github.com/mozilla/pdf.js which was not bad last time I used it, but it all javascript so performance isn't up to par with native. Also printing is not great and I don't think they have implemented a SVG backend yet for better printing. On the plus side you can embed it in your web app if you want and have more control over the viewer.
Chrome is not too bad these days. They 'forked' the foxit codebase and unless you need some weird features, chrome should render the page accurately.
The margins are specified in the page data in the document.
