Hyphenation for British and American English

I am writing documents with British and American spelling, and I have noticed that some 'common' words are not hyphenated. Examples include 'quar-ter-ly', 'pro-pen-si-ty', 'eu-ro-pean'. This can result in too much interword space (in my opinion), and I have to identify these instances manually.

I want to make sure that I am using everything correctly. For British spelling I use something like:

\documentclass[UKenglish]{scrartcl}

\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{csquotes}
\usepackage{babel}
\usepackage{hyphenat}

I know hyph-utf8 and load \input{ushyphex} for AE documents.

I have the following questions:

• 
  

  For BE, is loadhyph-en-gb loaded automatically when babel is loaded with british spelling?

  
  


• 
  

  Is there anything else I can do to ensure that some 'common' words are hyphenated.

  
  


• 
  

  If not, is there a way to identify where the typesetting could be improved so that I can create a hyphenation pattern myself?

  
  

Some related questions: LaTeX Hyphenation, Why does \usepackage[british]{babel} change the hyphenation to wrong?, How to add global hyphenation rules?, Where can I find a list of English hyphenation exceptions?