What do people expect from a Boffer LARP?
That's pretty simple. They expect a bit of escapism whe they can bash one another with padded weapons. If they didn't want that, they'd play a tabletop game, or a parlour LARP, or something else. So this needs to be the crux of the system...it doesn't mean everything needs to focus around combat, but it certainly can't be ignored and can't be one of the unwieldy aspects of the game.
How do people interact in the game?
We're basically looking at those same big questions that come from designing any game...what do the players do?...what do the characters do?...what does the GM do? When it comes to player interactions, the will cetainly be the combat between characters (or characters and monsters), but do we want things like honour in the game (so that we know who has a reputation for being good or bad), do we want status (so we know who is "more important" in the game setting), do we want things like character influence over the world ("I'm high up in the merchant guild, she's got influence among the thieves guild"). Adding things like this allows for story potential, players can be fed infor ation through their associated status, influence, and other connections, it also allows those players who aren't as physically fit to have an influence in the ongoing stories of the game. I'm starting to think of the political machinations in someing like "Game of Thrones", where connections and webs of intrigue spread across the world, but violence can quickly disrupt even the most carefully organised plans.
If death is going to be quick and nasty, then we probably need to make sure that character generation is pretty quick.
How powerful do we want a starting character to be in comparison to a veteran?
Players like to see their characters advance and become more pivotal in the storyline as they continue playing. A veteran who has been at it for a decade doesn't want a "first game newbie" showing up with a dagger, facing them down on even terms, and certainly doesn't want to lose to the newbie in a fair fight.
Conversely, a new player doesn't want to be instantly slaughtered by a veteran for a single false move that was beyond their control.
Where does the system draw the line between realism, respective narrative importance of characters, and maintaining the ability to engage characters at all levels?
Do we want non-human races?
This one can be controversial. Some players love the idea of dressing up, wearing orc make-up, or adding pointy elf ears, othes love the idea of other playing other races but don't like to dress up. What happens when the six-foot player wants to portray a dwarf? Some consider the idea of race (rightly or wrongly) to be an anthropological throwback and a somewhat racist element of RPGs.
I like the idea of having cultures that define the possibilities of character education and thought patterns, but within a fantasy setting allowing races that apply different physiological modifiers to characters. This covers the nature and the nurture sides of the debate.
How violent should combat be?
I never want a single shot instant kill. I don't care whether this is realistic or not, for narrative purposes and player enjoyment it's typically just a bad thing. If a player is able to carefully gain all the necessary bonuses through a series of manouevres then place their strike at the rit time and place, a kill shot might be possible, but even then I'd want the victim to be aware of everything that has led up to that point. If the victim is mature about the whole thing, I'd even consider some element to the system where they get a bonus amount of XP for their next character as long as the character death provides enjoyment or narrative twists to the wider game.
One of the intents behind the Camarilla organisation that I liked was the ability to improve your character by contributing to the organising of games. You earned "prestige points" that could be cashed in for character benefits. The system could be gamed, and I saw a lot of players abuse it over the years, so I'm not going to say it was perfect, but the idea was well intended.
I'd like to see something similar. Mostly because this is a game where players will be fighting monsters and going adventuring, so we need some kind of benefit to those players who choose to portray the enemies (rather than focusing on their own characters all the time). Other benefits might include helping other players source their armour and weaponry, or helping secure/maintain game venues.
There are many more ideas to think of when it comes to getting the basics right, but I'll leave it there for the moment.