<a href="https://github.com/shazahm1/Connections/blob/0.7.9.1/includes/class.output.php" target="_blank">class.output.php</a> file has extensive phpDoc for most of the methods including
<a href="https://github.com/shazahm1/Connections/blob/0.7.9.1/includes/class.output.php#L821" target="_blank">getAddressBlock()</a>
I suggest review this file and docs…
Here’s and example to output only the preferred address:
$entry->getAddressBlock( array( 'preferred' => TRUE ) );
You can not make a custom field in place of the “other” address type. That is just an option for the for the address type and that field can not be changed easily and I have no idea what would break if you did. Since the address supports 3 lines; what not just use Line 1 as the company name?