Here's a list of new creations that can be made:
http://starwars.wikia.com/wiki/Mutant

So far out of that we have the Massassi, Leviathan, Rakghoul, and Terentatek. I can see the Massassi working for SA1 but for the Leviathan it would need to be SA6 or so cause that's mighty powerful. Never the Terentatek, lol.

Then you also have the possibility of creating the new figure Sithspawn (http://starwars.wikia.com/wiki/Sithspawn). That would be cool for SA1, make them just a 10 point character that is an updated version of the Massassi that would make you actually want to play it.

While not quite Sith Alchemy, I can totally see a non-living version of the power used by a Kazdan Paratus to make Junk Golems.

I like that idea! It can be called either Junk Droid Master. Tier 1 could be a simple Junk Droid (http://starwars.wikia.com/wiki/Junk_droid) that is a little bit better Battle Droid. Tier 2 would be Scrap Guardian (http://starwars.wikia.com/wiki/Scrap_Guardian). Junk Golem would be Tier 3. Tier 4 could be the Junk Titan (http://starwars.wikia.com/wiki/Junk_Titan).

Yep, another use of those really bad huges.

Palpatine wrote the book on making monsters - litterally, he did, look it up in jedi versus sith - so I could see a sith alchemy 5 where he turns an allied stormtrooper into an Imperial Sentinel......that'd be awesome

I quite like it. I would suggest this, though (simpler):

Sith Alchemy 1 (Replaces attacks; 1 adjacent enemy with 20 HP or fewer joins this character's squad and gains savage for the rest of the skirmish)

The main thing is to create the Nanobeast as an independent entity and then go back use their stats for victim. Then go from there. I wouldn't want someone to be back to normal hps (might be more defined as just keeping the remaining 20 pts) or still be the same character. They should be deficient as they aren't completely in charge of their faculties.

Imperial Sentinels would defineately see play then.

Well other than the character that has it now and maybe 1 other Sith unique, this is not something I would wish to see again ever. However if a new character did get it then something that gives you the chance to bring in a creacher the same size of whatever you just defeated. It would have to be on a very expensive character though.

The good news for MOST of the SA potential creatures are that they don't spawn others. Outside of the Technobeasts (Belia) and Rakghouls (Muur/Morne), they were created from something to only do one thing: kill.

Now, if Death Troopers are created, which would open another can of worms in the spontaneous creation of 0 pt adversaries from defeated pieces, then there could be potentially 3 versions of roughly the same mechanic.

For Massassi Sith Mutants, I would expect that Exar would create them from say Massassi. I don't know, and I haven't fully read the Tales of the Jedi graphic novels, if there are any instances of creating them from other beings besides the Massassi.

As for the fun speculation of Palps and the Sentinels, it would have be a heck of a trick to pull off (maybe Force 20) to create something like that spontaneously. If they were, they should be considered "activated" so as to not have a monolith crushing things immediately.

There is also Vul Issen from Legacy that also practiced a small amount of SA with the Sea Leviathan. I hope we won't have those running around.

Of course, this is all speculation.