user57023: 1 - Can I run the BitCoin daemon (before KDM is even started)?
2 - Once I've started KDM, can I then run the GUI which will attach to the daemon, so only one BitCoin 'app' actually working?
3 - Can you get a status report from bitcoin-cli, similar to the qt-app (status of catching/caught up with blocks etc...)
Following the BitCoin Install Guide , I ran the qt-app after installtion, it worked fine. I tried the daemon after and got issues with 'no cookies' / problem with rpc authorisation.  I've also stopped the qt-app, then tried the daemon, it worked fine, then tried the qt-app and it complained something was already connected to the default port.
What is the correct order of running it, note the machine is on 24/7 (minus the desktop).

user2306: 
1 - Can I run the BitCoin daemon (before KDM is even started)?

You can run the non-graphical bitcoind daemon with or without starting KDM first.

2 - Once I've started KDM, can I then run the GUI which will attach to the daemon, so only one BitCoin 'app' actually working?

No. You can stop bitcoind and start Bitcoin-Qt, though.

3 - Can you get a status report from bitcoin-cli, similar to the qt-app (status of catching/caught up with blocks etc...)

Yes. 
bitcoin-cli getblockchaininfo

(Source.)

57023: <p>1 - Can I run the BitCoin daemon (before KDM is even started)?</p>

<p>2 - Once I've started KDM, can I then run the GUI which will attach to the daemon, so only one BitCoin 'app' actually working?</p>

<p>3 - Can you get a status report from <code>bitcoin-cli</code>, similar to the qt-app (status of catching/caught up with blocks etc...)</p>

<p>Following the <a href="https://bitcoin.org/en/full-node#other-linux-distributions" rel="nofollow noreferrer">BitCoin Install Guide</a> , I ran the qt-app after installtion, it worked fine. I tried the daemon after and got issues with 'no cookies' / problem with rpc authorisation.  I've also stopped the qt-app, then tried the daemon, it worked fine, then tried the qt-app and it complained something was already connected to the default port.</p>

<p>What is the correct order of running it, note the machine is on 24/7 (minus the desktop).</p>
 2306: <blockquote>
  <p>1 - Can I run the BitCoin daemon (before KDM is even started)?</p>
</blockquote>

<p>You can run the non-graphical bitcoind daemon with or without starting KDM first.</p>

<blockquote>
  <p>2 - Once I've started KDM, can I then run the GUI which will attach to the daemon, so only one BitCoin 'app' actually working?</p>
</blockquote>

<p>No. You can stop bitcoind and start Bitcoin-Qt, though.</p>

<blockquote>
  <p>3 - Can you get a status report from <code>bitcoin-cli</code>, similar to the qt-app (status of catching/caught up with blocks etc...)</p>
</blockquote>

<p>Yes. </p>

<pre><code>bitcoin-cli getblockchaininfo
</code></pre>

<p>(<a href="https://bitcoin.org/en/developer-reference#getblockchaininfo" rel="nofollow noreferrer">Source.</a>)</p>
