Issues with font and IE not playing engage interaction and MP4 video

Hi

I am testing Articulate 360 Storyline 

I have a number of issues.
1) Working with IE - despite being version 10 or 11 the engage did not work and a link to an MP4 video did not either

 

2) I have built with text as arial but on publishing on Firefox and on all mobile devices it does not show arial it shows another font.

 

3) The background changes to a very dark background for tablet and mobile devices - it is fine on the preview - which makes the text very difficult to read - is this something to do with the responsive player?

 

Please could you let me know whether these issues can be solved.

 

Hannah Moore