1mana monsters

Rather than go quote crazy I'll just address your quote by the 3 parts I devided them up into:

Part 1: Fair enough, I over reacted with the concept of 2 per color considering almost half of all of grey's 1 cost monsters are just variances of NPC.
The problem is that it's VERY difficult to make a 1 coster usable based on stats alone. For example, what would you make the stats of a 1 coster dark monster? Generally hitting 20 damage is taboo'd for a cost of 1 as that bleeds into the 2-cost range. You'd need to make it something along the lines of 19/1 and "does an extra 6 damage when damaging directly". I can see at the very least nerfing the effectiveness of the ability of 1 monster from each color to give it a higher stat focus; but outright, I think 1-costers just aren't good without abilities of some sort.

Part 2: Alright, I can at least see your point on this. Having a Gremlin, a K-Army Guy, and a Boomboxen out all at once would mean contemplating 3 distict abilities that are not seen on any other monster (or at least aren't common) and that might turn away players thinking the game is overly complex.
However, as far as I know, monsters costing 2, 3, and 4 mana can be plain beatstick and still useable. With 1-costers the problem is that we hit a point where the cost of a card is higher than the mana cost in terms of justifying use.

Part 3: In my defense, you said, "...what a 1-mana creature's stats should look like before adding any abilities." In the context of that, I assumed you ment we'd need a basis for what stats to give to ability 1-costers. Just like we don't use Hero 5L to justify Ardam 5L's stats, using a vanilla 1-coster isn't a good way to determine the stats of an ability 1-coster. I think we have enough of a variety 1 costing monsters with abilities to use as a precident for the stats of the 1 costers we're going to add abilities to and balance.
And a note to anyone reading this besides Ultros, I editted in the other 1-cost cards after posting and searching through Tamdrik's card searcher.

As for Kelar Citizen, Noble Sacrifice prevents damage, this avoids it (meaning the attacking monster won't be hurt by the defending monster). Not to mention the Drow (if I'm allowed to compare them to the Kelar) are tipically associated with being able to bend/blend with shadows and hide. This doesn't really fit the justification for the theme, but it does justify using entrenching for dark elves.