AD&D an introduction

[Narmoth]

Actually I have a few questions.

1) Which system is better suited for the actual roleplay and not number crunching?

As said, this depends most on the players and not the rules.
The thing with AD&D is that the rules are not coherent, but rather a set of rules for each different thing. So I can change them or ignore them as I see fit without disrupting the game system.
2nd ed is in that way a more homebrew-friendly system (in my oppinion)
The players option expansion gave a lot of room for powergaming, but by simply adjusting the monsters, it equals out pretty well.
One warning: don't give out xp for money earned. Ever.
It makes the players exceptionally greedy.
Give out plot acomplishment xp that reflekts the importance of the plot vs the monsterkilling.
I give out large sums of xp, equalling to several major battles for each large story quest so the players consentrate on the quests.
The character development isn't perfect in 2nd ed, as each character is sett in his class, fulfilling a sertain role. On the other hand, you won't end up with a whole group of fighter/mage/thief/clerics as it inevitably happens in 3.5, where all people play a half elf / something really weird / necromancer / paladin.

2) I know a bard can specialize and become a lot of things in 2nd Edition (mainly because I have that book from a friend), but is there any class the bard can become that you, personally, think is just cheese?[/QUOTE]

The bard isn't very balanced character in 2nd ed. The best balancing of him is to either disalow access to wizard spells, limit the school access or the level progression.
A bard with mostly illusion and charm spells, with the current spell progression, or give him half the spell progression that's stated in the book would balance him in a group having a mage but lacking a thief.

I've heard that a Bard who just pretends he's a wizard can be pretty broken. Because he levels up enough faster than a wizard that he can actually outperform the wizard in blasting damage.

Not if the rules for learning spells are followed, as he will usually have lover inteligence than the wizard. Still, this is a problem, and you shoud restric the 2nd ed bards access to spells in some way.
I believe by the way that this unbalancing of the bard is the root of tha bard-hate in the rpg community.