You could make a button which uses the SysInternals Strings.exe:
(See: How to add example buttons to your toolbars and menus)
<?xml version="1.0"?>
<button backcol="none" display="both" label_pos="right" separate="yes" textcol="none">
<label>Strings</label>
<icon1>#read</icon1>
<function type="batch">
<instruction>"C:\Windows\System32\strings.exe" {filepath$}</instruction>
<instruction>pause</instruction>
</function>
</button>
The result appears in a DOS window but you can still scroll around in it and copy & paste things so I find it good enough for something that I don't use very often.
Not at the moment. The viewer requires a byte-order mark at the start of unicode files.
Maybe a "Force Encoding" option in the Text viewer's context menu would make sense. (You can request such a thing via GPSoft's site.)