likeliness of this?

Zero to none.

For enlargement you would have to add molecules or breakk some apart making it mushy. For a shrink ray you would have to remove them so it would be like a large image with parts removed:
http://web.brno.cz/kamera/hugeimage.jpg

where would you put the excess matter in a shrink ray and where would you get the extra matter for the growth ray

the closest thing i reckon is a duplicator that has adjustable sizes

Climb inside a wool press and turn it on. (I haven't worked out the enlargement part though)

Considering that atoms are mostly empty space (nucleus made of protons and neutrons surrounded by a cloud of electrons), if you found a way to manipulate how much empty space (how closely the electrons orbited the nucleus) I guess: theoretically possible?

Edit: Upon further research into this, the Pauli Exclusion Principle explains why this is completely impossible, and now I feel dumb.

Considering that atoms are mostly empty space (nucleus made of protons and neutrons surrounded by a cloud of electrons), if you found a way to manipulate how much empty space (how closely the electrons orbited the nucleus) I guess: theoretically possible?

you would have to manipulate their charges. and everything will be either really dense or really light

hmm...

I don't think a shrink/enlargement ray per se would work. You can increase the volume, but not the mass. In other words, you're only moving the atoms farther apart/closer as you displace them.

Shrinking something down would make a very dense material. Enlarging something might make the atomic structure highly unstable, causing the object to return to it's original state, collapsing/skewing under it's own weight, or maybe even de-atomizing completely, causing the structure to change it's chemical composition, perhaps even causing a violent reaction.

Given some objects like metal cogs or marshmallows enlarged to furniture might withstand the process, any application you used it for on a more complex chemical compound(such as a marijuana bud or your penis), could make for a disastrous outcome.

A more practical way would be to 'scan' an object, scale it to the size you want with a computer, let it re-hash the atomic structure to get it to a proportional density, and then materialize the copied shape.

I can't really think of a single way to duplicate atoms. I mean you cant exactly copy and paste...

However who's to say it would be impossible for somehow to get the closest match to said atoms (The simplest objects would be much easier of course) And to figure out how to get the seperate but identical atoms to attract and form together into a single mass. Using say a uniform object(lets say a piece of plastic )like someone said above) all we'd have to figure out is what keeps the atoms together and somehow join the two separate parts in the same way.

Congratulations you just connected mass, not created mass.

So enlarger ray? Impossible. Fuse ray? More likely