Was Lucent Liminid ever on the table for There's: Beyond Death? Seems like a missed opportunity.

The creative sadly isn’t a great fit. We did talk about it.

You've said that you want to do contraptions exactly as worded on steamflogger boss... But future sight was riddled with things that ended up being done similarly but not exactly (tarmogoyf ~ Delirium boosters, sarcomite myr ~ esper shard, ghostfire ~ eldrazi, lucent liminid ~ nyxians, virulent sliver ~ infect). Why are you making Steamfloger Boss completely immutable while you solve contraptions? Isn't this just making something (that matches exactly) simply to show you can (bad design)?

Doing it in the very next set regardless of whether it fits or not is doing it to prove you can. Waiting for the right spot to properly solve it, is good design.

"Because Lucent Liminid breaks the rule of all enchantment creatures - it has to be both creature and enchantment." Lucent Liminid's card literal says "Enchantment Creature - Elemental." What do you mean?

Nothing about it had the functionality of an enchantment.

Green is supposed to use its own creatures a way to remove other creatures. However, Theros has made it so green has straight creature removal thanks to its ability to remove enchantments. How do you justify this, but you hate that Anarchy and Chaos Warp let Red deal with enchantments?

Green has and always has had the ability to destroy enchantments. Enchantment creatures are thus vulnerable to green’s enchantment destruction much like artifact creatures are vulnerable to green’s artifact destruction. The only new thing added by Theros is the existence of enchantment creatures (barring Lucent Liminid which technically is from the future).

My issue with BNG is that the enchantment type feels mechanically misused. Bestow guys felt like enchantment creatures, and Gods felt like enchantment creatures, but as we've moved further into the block things have gone downhill. The Archetypes are just creature lords with funny templates, and the Spirit of the Labyrinth cycle are literally just creatures. It feels like the enchantment type is being used purely as a placeholder for "Nyx" on cards where it makes as much sense as Lucent Liminid.

Except unlike Lucent Liminid they do have an enchantment component. I understand that many creatures also have global effects but I wanted to make sure all enchantment creatures had some enchantment-ness.

Is Lucent Liminid sort of like Nacatl War-Pride, Ghostfire, and Sarcomite Myr in that it represents a card that could have been from a future set, but the set took a different direction?

Not every Future Sight timeshifted card 100% captured the future it hinted at. Some showed one aspect that got used while including other aspects that didn’t. 

why didn't for completionist sakes didn't you make a token Lucent Liminid?

With few exceptions, we don’t give names to tokens.

Does Lucent Liminid have any chance of being in the set? Or are all enchantment creatures either gods or god-creatures (with bestow)?

All enchantment creatures in the block (with the sole exception of token creatures because we don’t like putting text other than creature keywords on them) have both an enchantment aspect and a creature aspect. In other words, it was very important to me that enchantment creatures be both enchantments and creatures. That does mean it’s not looking good for Lucent Liminid.

What about Lucent Liminid? should we expect to see more Enchantment Creatures on the way?

I’m not a fan of Lucent Liminid because it doesn’t feel like an enchantment in any way. I believe we will do enchantment creatures when we find a way to make them feel like enchantment creatures.

What exactly is the problem with designing enchantment creatures?

The tricky part is you have to make them feel both like a creature and an enchantment. That was my big pet peeve with Lucent Liminid (from Future Sight - the only enchantment creature we’ve made), it didn’t feel at all like an enchantment.