"New" OD&D campaign

Over the past three months, I've been running a weekly Original D&D game at my FLGS, Misty Mountain Games.  Like my previous attempt in Ames, I started with just one player, Gene.  Gene had showed up to one of the Madison Traditional Gaming meetups, and had a sufficiently good time that he was interested in a regular game.  I was initially worried about having only one player, but Gene seemed to be ready to take on the challenge, so off we went.

Rather than the Southlands setting I had used before, I went with a very simple set-up: "Here's the dungeon - the Tower of Xylarthen - and nearby is the village of Kingsbridge.  It's tiny and on the edge of everything.  Go kill some monsters and get their loot."  Gene rolled up two characters: Kyle, a halfling thief, and Grollan, a dwarven fighter.  I rounded out the party with Garric, an apparently fearless (or foolhardy) human magic-user with 1HP.

Some of my inspiration for this came from a series of posts on Ars Ludi about the West Marches campaign.  I figured that my weekly open game would lend itself to that kind of set-up, and I hoped that having a relatively simple game would be less work for me as a referee (which turned out to be true).  I also made a point of shamelessly swiping stuff from my collection of gaming magazines and materials, and then filing off the serial numbers to fit them into the campaign.  A lot of this was done simply to re-familiarize myself with the rules of Our Favorite Game, and to avoid me making a big creative investment in the world (an old mistake of mine).

Adventuring with just one player has been fascinating.  I've ended up re-sizing encounters to make it possible for an adventuring party of 3-4 characters to survive, though I haven't completely fudged everything.  I've also encountered real questions dealing with all sorts of stuff:

• Combat: should initiative be just a d6 roll, including or not including a Dexterity bonus?  What about weapon length?
• Base mechanics: who gets to roll for what?  Do I roll for opening doors?  How many chances do characters get?
• Experience points: awarded for killing monsters, check.  What about monsters defeated or thwarted?  What about experience points for gold?  What about taking character level and dungeon level into account?

We've now gamed about a dozen times, and have added a player, Dave.  Now that we've doubled the size of the player group, we'll see how things evolve