In 7 my characters get hungry super fast, is it because I'm running everywhere? If I walk would it deplete slower?

In 4 I was fighting a demon, who was fleeing after two hits, but as it was fleeing it was still attacking me. So I killed it. Does this still count towards losing Honor stats? I mean, I give it mercy and in return it stabs me in the back, so really it shouldn't count.

I don't think you're supposed to let evil creatures like demons get away. Mercy counts towards being attacked by animals (rats, snakes, spiders). There you should stand your ground, but don't chase after them.

You also don't need to worry about raising your honor. It will raise automatically by questing (getting runes, stones etc). As long as you don't steal from chests in towns, attack non-evil creatures or cheat the blind reagent seller, you'll get you avatarhood in honor by simply questing.

If you want to see, how the virtues work in U4, take a look here: http://wiki.ultimacodex.com/wiki/Virtues_in_Ultima_IV

Of note, in Ultima 4, if you run from a battle and see the message "BATTLE IS LOST", your Valor has decreased because you ran from an evil creature.

If you run from a non-evil creature, you won't get that message, and you won't lose Valor. I believe running from a dungeon room is also safe.

Of note, game-overing to an evil creature costs virtue (IIRC), but game-overing to something else (like those orbs you can touch in dungeons) does not and will actually, I believe, boost Sacrifice. So feel free to death warp as much as you need to (but be aware that you will lose unequipped items and your gold will be set to 200).

http://ultima.wikia.com/wiki/Food_Values_in_Ultima_VII

Just ignore what it says about the goblet. The F hotkey will automatically use it until that character is full.

A caveat with the (F)eed command in SI: it'll automatically use edibles from your inventory but this can be a problem if it chooses the bottle of wine that appears in your inventory at the beginning of SI (since it's harder for anyone to identify it if you don't have it anymore), or your garlic (which is a much bigger problem since this is a reagent for your spellcasting - though if you have the Ring of Reagents, it won't matter anymore).

Hence, you might want to drop both of those before using the command.

I don't know if Exult prevents either or both of those from being eaten this way, so be careful!

Identifying the wine is optional, and the garlic is very unlikely to be used if you have any other food, which you should.

From memory, when it comes time to identify the wine you can also just pick up any similar wine that looks identical and the game will accept it (and there is plenty of that type of wine at the proper location)