Homebrew PCBs

I'm re-doing some components I previously created (in Eagle, but this
probably applies to other CAD pacakages as well).  The actual
components, MiniCircuits SBL-1 RF passive mixers require several
signal to be connectected externally.  This is an 8 pin through hole
device.

Two of the pins are for discrete signals.  Two other pins are for one
signal, and four pins are ground.  In Eagle, I've designated the
ground pins as SUP (supply) and the other four as I/O.  I would think
there should be a way to tie the two I/O pins together in the symbol
that are supposed to be connected together extenally, but I haven't
run across any symbols that tie pins together.  I have them tied
pictorally in the Symbol drawing.  Also, I'm not sure if pads can be
tied together in the Eagle Package for the device.  I can lay
additional pads down that overlay and graphically link the ones
defined for the pins, but they aren't logically connected when the
Device is defined; they are just sort of lying there.

Without tying the pins and pads together in the Symbol/Package/Device
definition, I have to remember that the two signal pins have to be
tied to the same external signal, and the four ground pins have to be
tied to ground, and not leave one or more unconnected.  It's not a
real big deal, just a convenience.

There is a note in the Eagle Help topic on pins that states if any pin
are defined on the Symbol as SUP (implying GND signal)that these will
be automatically connected to GND as a net if a Supply symbol is used
on the schematic; for example +12V, I presume. That's something else
that's news to me.  I've used Supply many times, and I've yet to see
any component automatically tie to GND.

Any ideas?

Ted