Jessie - Mate - LibreOffice Need larger fonts everywhere

[Richard Owlett <rowlett@cloud85.net>]

I just installed Jessie with Mate DE.
I had no trouble setting font size for menu-bars/drop down menus/etc.
I wish to use LibreOffice Calc.
Two problems:
  1. I need the text of Help Screens to be large enough to read.
  2. I want to force a specific default Font Family and Font 
Size for cells on
     *ALL* spreadsheets. I can set for specific region of 
current spreadsheet only.


Secondary question:
Any way to force minimum Font Size for any operator input 
independent of application?

TIA