This sounds great but I could probably only play on weekend mornings. How often did you expect to hold sessions?
Well, as this is forum game I do intent post daily if I can although weekends I post less.
I don't have all the character details filled in, but here are the mechanics.
Looking good for me, proceed finish it :).
Is this going to be IM game or forum one?
Forum one, I cant probably handle IM one so well

.
I'm interested, but is this just a test run, or are you going to make an actual campaign?
It is kinda both. I make a some interesting scenarios with
potential for start point for campaign. If game proceeds nicely I start build actual campaign. I have run RL a 4th edition games but not in 4th edition Faerun.
Anycase as note I roll single iniative to the goblins and single iniative on the heroes. It determines which side acts first (to keep encounters simple) and the one who posts first after my update/after enemy turn also acts first in that round (so one round ranger posts first and so acts first in that round and then next round fighter is first because he posted first). So keep that in mind when you post (so mage's case they cant unleash massive AoE after most melee members of party engaged enemy in close combat or else own party members suffer friendly fire from own party member).
Anycase iniative of the two groups is counted on 'average' modifier which is combined iniative value of both groups (with pens and bonuses included) and then I roll d20.