- Change animosity so that you're always able to charge, but may squabble if you decide not to. I'm quite alright with some of my units not being able to move forward at times (it's part of the charm) but I've always found it very un-orcy to have an enemy well within charge range, but instead of charging it, your units start to fight with each other instead.
- More magic banners and lower the point requirement for the goblin ones to 25 points. The fact that you have to dedicate your BSB in order to get your goblin unit poisoned attacks for example, means that the goblin banners are rarely ever taken. I'll continue this line of thought in the goblin section.
- Have Common Goblins include shields for the 3 point a model cost. Right now, Night Goblins is the only unit type of goblins anyone would bring, because regular goblins don't have fanatics nor nets, two very useful options. Instead they can get a +4 armor save in combat, but for extra cost, meaning you pay more for a unit that's still not as good as night goblins (nets are simply better).
Keeping them at the same point cost, but allowing common goblins to pick a magic banner for 25 points, would make them more useful. Giving them the ability to become Stubborn on LD6, or have poisonous attacks would hardly be overpowered by any means, but would make them a more attractive option and encourage more diversity amongst your goblin players.
- Either lower the point cost or improve the stats for some special units. Most O&G players would agree that both Black Orcs and Boar Boyz are too pricey for what they do. In short, I'd say that for 13 points a Black Orc should get an additional attack (the most combat proven orc in Warhammer is still worse in battle than a Lizardmen core trooper, and more expensive at that) or they should cost less. Right now, they're not strong enough to work as a small shock troop, and too expensive to take in large blocks.
Similarly, a Boar Boy will give you a WS3 and S4 attack on the charge, with a 3+ armor save and that's just not going to cut it for a cavalry unit as they won't break anything. In order to get the most out of the unit, you need to take them in units of 10-12, preferably with a character for the extra punch, and that quickly means investing 400 points in it, which they'll struggle to get back. Either they need to be upgraded to heavy cavalry, with +2 save and S5 on the charge, or they can be kept as medium cavalry but lowered in price, so that it's actually sensible to take large units of them.
- Finally, lower the pressure on special choices. O&G live and die on their special choices, but often find that they're hard to come by seeing as how we've got 9 different units but only 4 slots. Since we can't leave home without war machines (since we struggle against monsters and tough armor), we have about 3 choices to get our share of squigs, chariots, cavalry and shock troops in, and there's just no room for all of them. Especially since chariots no longer are 2 for 1 choices, it's even harder to get enough of each unit into a list. My suggestion would be to make either boar boyz or chariots core choices. It's that way for Beastmen and Empire, why not for the Orcs & Goblins?
Those are my thoughts on some of the highlights debating how to improve the army book without changing things all too much. As they say on the show, the army has got some good units, great and characterful magic items, it just needs a few tweaks in order to compete with the rest of the armies out there. I really recommend that you listen to the Bad Dice Podcast on the subject, the guys there do a great job.