Well the rule changes would be wishlisting if they were in the rumours section.

These are just house rules
Grey templar, I'm glad you like the Hitch a Ride rule. It's my favorite of these House Rules. It's flavorful and offers all kinds of terrific tactical uses (though they require a bit of finesse - not simply a "march across the table for the win). I think a "ranked unit" of Ogres, (i.e. with a second rank) would transport a unit of 20 Gnoblar Fighters (3 per Ogre with an extra two if you have a champion). Hunters, being heroes and having a tighter bond with their Trappers, can transport up to 9.
The downside to Hitch a Ride? If your unit is destroyed by shooting, you lose 210 pts for the Bulls and 40 pts for the Gnoblars.
Drear, I admit, LA+Gutplate+Ironfist+XhW (3+) is pretty crazy. However Warriors of Chaos (of which no one in our friendly, balance-conscious group considers overpowered at 15 points apiece) get a 3+ save if you add a shield, and frankly two of them could go toe to toe with Bulls, Ironguts, Leadbelchers and possibly Maneaters. WS 5 BS 3 St 4 T4 W1 I5 A2 Ld8 -- FTW?
From that perspective the average Bull, at 35 points a model, doesn't seem that expensive. Thee two models have the same armor save while the Chaos Warrior has better stats all across. The only edge an Ogre has is more attacks (however its four attacks vs. two for Warriors=a wash). Ogres cause Fear -- but it wouldn't effect the average Chaos Warrior very often (especially if in range of their General). Bull Charge and movement also give Ogres an edge. But against T4 Warrriors with a 3+ save, that's still not much.
But Chaos Warriors are at the extreme end of core troops, you say? True. What about Empire Swordsmen? We all know humans are the basic statline in Warhammer. Swordsmen are a little bit ahead of the game (1 pt higher for WS). But for 6 points per model you get WS4, BS3, ST3, T3, I3, A1 Ld 7. Very close to a Bull (aside from Toughness and Strength). So you can get almost SIX! swordsmen for the price of ONE Bull. That's five to six WS 4 attacks with a 4+ save. Six swordsmen against ONE Bull is also pretty even -- even with my house rules.
Think about Orc boyz. 6 points apiece. Nearly identical statline as a Bull (aside from wounds). Seven points with a shield (4+). Five boyz vs. a Bull is even with my house rules.
Consider that each of these opposing units can also get rank bonuses much cheaper than Ogres (an Orc rank for the cost of one Bull). Swordsmen and Orcs are static combat rez machines. Twenty swordsmen at 180 points vs. six Bulls at 210 have static combat rez of +3 for ranks and +1 for outnumber (and the Bull are no longer Stubborn or Unbreakable). Even with one rank bonus, Ogres are at a disadvantage unless they get 2-3 wounds from Bull Charge.
In the end, even with a Gutplate and Ironfist (from Leadbelchers do not benefit) Ogres are simply lower tiered, point for point, than the average units in the game (Humans and Orcs). Let's not even go into shooting units (esp. all Elves, Dwarf rifles, Empire Handgunners) Most shooting will wittle down the average Ogre unit before it gets the charge, especially armor-piercing or St 4 weapons.
In fact now that I'm writing this, I think I've realized a powerful rule to balance out our lack of combat rez. Change Bull Charge to "An Ogre unit with a second full rank negates its opponents ranks when calculating combat resolution." This would completely replace Bull Charge. The only reason I don't like this rule is it destroys the flanking, bait-and-flee nature of our gameplay. However, it is much truer to the fluff, as Ogres are not noted for their tactical skills. Personally I don't like like the rule (I think it would be commonly decried as cheese), but you have to admit it would solve some problems.
Anyways, just my ideas and more justification for these House Rules. Sorry they are so wordy.