@Bryan, being attacked during resting is a point, though for some reason that never bothered me in Entombed 1.
@Jason, as I said I'm a fan of the winning streak idea, because it both encourages calculated risk as you said, and also means there are always new things to achieve in the game, plus it would be interesting to have the possibility of acquiring better quality items at lower levels.
As regards the number row, personally I always used the number row for body part targeting rather than the numbpad. This is sort of generally a thing with me, sinse I learnt computing mostly on laptops, and even on a desktop usually have all of the supernova speech commands on the numbpad so don't really use it in programs, but it's just a preference.
One other thing to consider, especially if the "how far can the player go without wussing out and returning to town for a complete heal" type of mechanic is used, is what part town plays in the game.
The entombed one economy got a little crazy, even the most awsome splendid enchanted steel items wouldn't fetch much either in town or in the shops in the dungeon, but then the town shop would rarely have anything useful, heck even healing or mana potions were ten a penny, though if (as I hope), more status effects and potions to cure them get added to the game this could change because then consumables could be more necessary.
One system I rather liked is that in Anband. there are 6 basic shops such as the armourer and blacksmith, the general store selling food and torches (sinse both light and food are things in that game), a mage's supply shop, a temple and an alchemist selling potions, but then there was the black market.
as you went down the dungeon, each of the six shops would have items approximately your level, the same sort of thing you could find on your current floor. The black market however was a wild card and could have either far better or far worse items, however at ten times the price.
Angband also has a rather nice option, that you can either cart stuff up to the surface to sell, (a dicy proposition given Angband's limited inventory space), or use the "nosell" option which makes it impossible to sell to shops, but vastly increases the amount of gold you loot from enemies, find in chests or can dig out of mineral semes in the wall.
I'm not sure what would be good for entombed, but I do like the idea both of the black market as a way of getting other stuff, and I admit I do like the option to simply find treasure in the dungeon rather than carting a truck load of enemy weapons around to sell.
Btw, what do people think about light? I know Entombed one didn't have a light source in the game, but it always did strike me as a bit odd, and if we're talking in terms of abilities to find secret doors, look out for traps in the dungeon and distinguish things that are hidden maybe light should be considered as needed, at least for some races (sinse most humans don't do well at finding things in the dark without the practice some people have), actually thinking about it having most races either need light or need to see in the dark but then having some classes have a "blind search" ability which meant they could get on without could be sort of amusing and again, mean more environmental interaction.
Oh yes and if you couldn't tell I'm very! excited about this game .
With our dreaming and singing, Ceaseless and sorrowless we! The glory about us clinging Of the glorious futures we see,
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)