I like the idea of lots of plot hooks - however some important thing to keep in mind are that
1. this is our first go at this
2. the amount of material translates to a general price tag - so if we make tons of material we'll have to set the price high or we will dissapoint with the next scenario that isn't as full of info. And if the price is high we'll probably turn away a lot of customers who don't know what we deliver. Our strength is in numbers (which can also be a weakness though) and in the high amount of maps we're going to throw in. (want maps of the characters - we got'em too )
3. this our first go at this

I posed the question of level to get an idea of what kind of scenario people would want - I like the start from 1st myself and it feels like most like that idea. I don't feel there is any problem setting a level for the adventure, quite the opposite - having the adventure to generic is in my eyes a weakness making us loose focus on the task at hand and making it harder for the GM as he has to adjust a lot of stuff himself. Yes, the experienced GM will have no problems with that - but he'll have no problems converting the challenges to a higher level either. The same goes for the choice of system as well - if we set it for D&D we cater to the largest user group and everybody playing other types of games would like be used to converting to their system anyway, whereas I could tend to think that some D&D players would choose not to buy the generic game cause it wasn't for their system. Especially 4e players I'd think.