<p>I'm not a high rep user on SF (yet!) but I am on SU. And the answer, quite simply is, you don't need to answer all that many questions to be a high rep user. On SU, I went for one good answer a day, maybe 2. On superuser I have 1571 answers for 39,111 rep in a total of 1063 days on the site (for comparison, I have 1934 rep on serverfault  for  79 answers over 718 days). At some point of time I hope to be able to answer more questions here, but its still a factor of skillset over time.</p>

<p>I have a few tricks - I love RSS feeds for sites I'm new to - its a good way to get a quick overview of active questions including the content of them. Many also recommend specialising in specific sorts of question.</p>

<p>You don't need to spend lots of time to get rep. You just need to work smart. </p>

<p>As for employment prospects - I think <a href="http://meta.stackexchange.com/a/143585/135565">this</a> answer is a pretty good alternate view. Its a matter of how you sell it - reputation means little, but community involvement and varied quality answers may show an enlightened employer you have <em>skills</em> the same way a reference would. </p>

<p>Finally, a smart sysadmin keeps his employer happy, and works as little as possible. I will leave the implications of that as an exercise to the reader ;).</p>