4th Edition - Forgotten Realms Campaign

I'd like to collect some notes on my first 4th Edition Campaign, and what's working. I'd like for the blog to be primarily rules focused on what works and what could use some improvement from a rules perspective with 4th Edition.

First, some housekeeping. I'm running with six players, each playing one PC. I'm running in the FR, largely because of my own familiarity. I am going to use the "core" 4E books for as long as we can, because I really want to see how it plays "as it was intended". I'm also going to use as much as I can from WoTC, Dungeon, and FR. I like to run my games as funny, combat-focused, with some RP and backstory that moves the plot forward that surrounds the mystery and discovery for the campaign. It is fun doing that in an "updated" world that has pre-published setting info, as this adds quite a bit to the journey of discovery for the players, without me having to write/translate this information into the campaign world. I've started the campaign, as designed in Loudwater, with the Keep on the Shadowfell being a signficant contributor to the "low level" adventure material as well. I've got Scepter Tower of Spellguard as a fallback, and there are several adventures in the FRCG that I will work in as well. These will all combine together to allow the players to choose their own adventures, without railroading, but trying at every turn to tie the encounters together in a way that uncovers the mysteries of this campaign.

The players are Dwarven Cleric, Human Fighter, Human Fighter, Human Ranger, Human Wizard, and Tiefling Warlock. Of note, four of these characters have already begun to "multi-class", so there is definitely something appealing here. I've not had any complaints with regard to "balance" and everyone seems able to contribute to pretty much every encounter and situation.