Unfortunately, I, too haven't been able to get unicode support properly configured in xterm. As a workaround, I ended up installing rxvt, which is available from rpmforge on EL distros. There's also a unicode-256color version of the program, which works great for me. Here's the description:
Name : rxvt
Arch : x86_64
Epoch : 18
Version : 2.7.10
Release : 2.el7.rf
Size : 326 k
Repo : rpmforge
Summary : Color VT102 terminal emulator for the X Window System
URL : http://www.rxvt.org/
License : GPL
Description : Rxvt is a color VT102 terminal emulator for the X Window System. Rxvt
: is intended to be an xterm replacement for users who don't need the
: more esoteric features of xterm, like Tektronix 4014 emulation,
: session logging and toolkit style configurability. Since it does not
: support those features, rxvt uses much less swap space than xterm
: uses. This is a significant advantage on a machine which is serving a
: large number of X sessions.
ArchWiki has useful information as always on configuration and use-cases.