What do you know of "realism"? Dig up some facts before you claim something is unrealistic. The historical area of engagement for a lance was thirty degrees; two-thirds of what it is now. Also, fuck no -- fuck. no. -- to any buff for cavalry. They're disgusting enough as it is. If you're having difficulty doing well as cavalry it is due to your inexperience, not a lack of power.
Maybe you are talking about couched lancing? I don't think you will find any evidence supporting the idea that for some reason, it was convention in the middle ages to risk death in keeping one's self from attacking an enemy until that enemy is directly ahead. It makes sense to restrict the longer lances to couching, but light cavalry world over were still operating with less unwieldy lances designed for a high stabbing motion in the ancient manner. In terms of gameplay, M&B simulates this quite well.
I think the "skill only" naysayers in this thread are probably content with picking off unattentive players. If you're killing 2hers and polearm players with a light lance at the moment, they should be advised to uninstall. I joined US a couple of days ago with a brand new char, to get it registered on the site and I killed 3 horses in one round with my starting sickle, 300 ping. 1h vs cav is probably a fair fight at the moment, but 2h and pole have no excuse outside a gank. It's very rare to be in such a bad position that you even have to downblock, in my recent experience.
The lance fov reduction was apparently put in place to make 1h cav more effective. 1h cav has not become magically more effective at fighting infantry, they can harry 1h inf, but they are still never ever going to beat an alert 1h or 2h inf 1 on 1.
Courser costs more than Transitional and cavalry balancing needs to take this into account.
To get any leverage you would need to keep the lance pretty much forward.
It was pretty ridiculous in native when I could ride full speed forward, and then stab behind me and do some serious damage.
I think you underestimate the momentum involved and as I say, overhead lancing was the norm for most medieval cultures.
In native, stabbing behind you gives a huge speed reduction, instead of 250% damage, you might end up doing 20%. It's not so ludicrous.
Edit: Since medieval paintings almost always show combatants facing each other, because of the gothic style, I doubt there are many depictions of sideways lance angle, but here's a guy couching over the fellow next to him.