How can I disable terminal resizing

To fix your Taglist issue, add the following somewhere in your .vimrc:

let Tlist_Inc_Winwidth=0

From the VIM documentation:

Window resizing with xterm only works if the allowWindowOps resource is
enabled.  On some systems and versions of xterm it's disabled by default
because someone thought it would be a security issue.  It's not clear if this
is actually the case.

To overrule the default, put this line in your ~/.Xdefaults or
~/.Xresources:

    XTerm*allowWindowOps:       true
     (note: this actually ENABLES it, you want to DISABLE, ie: false)

And run "xrdb -merge .Xresources" to make it effective.  You can check the
value with the context menu (right mouse button while CTRL key is pressed),
there should be a tick at allow-window-ops.

From my own experience with the Xresources, if you drop the 'XTerm' part, and just lead with the asterisk, it should also apply for any gnome terminals too. The gnome terminal has it's particular prefix, but I don't know it, maybe someone could comment with that info, but the *allowWindowOps: false line should help.