You do have a good balance of units, but your list definitely needs some tuning. The biggest problem you have here is that you aren't making use of detachments. They are our greatest tactical advantage and you would be wise to use them. From some rough math it looks like your list is aiming to be 2000 pts. The standard that most people use is 2250, so I would add in another 250 points. Here's my breakdown of your units and their equipment, along with my recommendations:
archlector,dawn armor,holy relic,great weapon
A 4+ rerollable armor save, even combined with a 4+ ward, isn't the best defense. I think that the best option for this guy would be the Armor of Meteoric Iron replacing the Dawn Armor and then the addition of the Van Horstmann's Speculum. This item is great for an AL and can dish out some serious hurt in challenges.
captain,handgun,plate armor,imperial banner
There is absolutely no reason this guy should have a handgun. Handguns are move or fire so in order to use it, his unit would have to stay stationary. He's also suffering from not enough protection with only a 4+ armor save. Mount this guy on a barded warhorse to at least bring that up to a 2+. I do love the Imperial Banner though, good choice
battle wizard,lv2,aldreds casket of sorrcery
This isn't a very effective magic item to use on your Wizard. I would give this guy either a couple of dispel scrolls or a Rod of Power (I'd recommend the scrolls, but both are good)
captain,barded warhorse,plate armor,shield lance,hand gun,ring of volans
This guy doesn't do much for you other than be kind of a badass and add some fightyness to a unit. I'd bring in some more magic by dropping this guy. Given your current setup, I think a second Wizard would be more beneficial than a Priest, but Priests are great too (especially when teamed with Greatswords). If you gave your other Wiz two scrolls, give this guy the Rod of Power and a Ring of Volans if you have 20 extra points laying around.
2x 20 halberdiers,shields,command
20 swordsman,cmnd
Halberdiers are not an ideal choice for your main blocks. If you really like the models, they work decently as detachments, but I would stick to Swordsmen for your blocks. I would up the unit count to 23-25, depending on where you intend to put your characters, but your goal should be US 25 at least once you drop them in there.
2x 10 hand gunners,mrksmn,lng rifle
These guys are okay. The long rifle is fun and can occasionally be worth it, but I generally find it to be a waste of points. If you still want two shooting units, you might drop the long rifles and make one of them crossbowmen for a bit of variety and flexibility with thier longer range. When it comes time to drop units to trim points though, these guys would be first on my chopping block.
5knights,cmnd
5knights,cmnd
Empire Knights don't need full command. The Champion accomplishes nothing at all except adding a signle S5 attack on the charge and the Standard Bearer brings +1 combat rez, your knights will generally not be charging things where they will need this. The best use of Empire Knights is either to kill softy support units that are giving you a hard time, to flank charge enemy units, or to be generally annoying and get in the way of enemy units. The banner doesn't really help at any of these tasks and it will end up costing you 100 VP in the event of the Knights losing a combat. The way to run Empire Knights is as "Vanilla Knights"; basically 5 Knights with a musican. Drop those banners and champs and you'll be good.
5 pistoliers/cmnd
Pistoliers are great. I would definitely pick up a repeater pistol for your champ. It will give him 4 shots instead of 2 for only 10 more points. I'd also consider increasing the unit size to 6 for some extra blastyness.
2x cannon
Of course.
With that extra 250 points you should be playing with, I'd add in some detachments to the blocks, preferably 9 man units of Swordsmen or Halberdiers if you're crazy about them for some reason and also 5 man detachments of Archers. If your pals insist on running 2000 pt games, I'd ditch the Hangunners for detachments. Check out the detachment tacticas
here for some great tips of using detachments effectively and also read up on all of the War Room articles here if you haven't yet. Best of luck to you!
