Well Knock isn't as reliable because it doesn't disarm the traps that are on locks. Yes you could do it from a distance but not always.
Well, if you got Mage Hand, Open/Close or Telekinesis, you may not find it a problem that you trigger a trap, since whatever it does is likely outside of your reach. Sure, maybe it'sa trap that will still hurt you in some way - but hey, the Rogue can also fail his thievery check. He doesn't get to automatically disable traps, he just has a chance to do so.
So the Wizard can have the rogue BAB, Saves, HD, Full Sneak Attack, Evasion, Improved Evasion, Uncanny Dodge, Trap Save Bonuses, Special Ability, and Tons of skills all at the same time?
I don't think so. The rogue is safe from the Wizard taking over his role and trying to keep another one.
You don't need the exact class features of the Rogue to replace him.
Sneak Attack, for example, is entirely unnecessary if you already have attacks (spells) that deal 1d6 damage per 2 levels (in fact, the Wizard has many abilities that deal 1d6 damage per level).
You don't need moderate BAB if you only make touch attacks or your spells require only saves.
You don't need Evasion or Improved Evasion if you have spells that grant you other ways to avoid damage, restore hit points, or create a hit point buffer. (Protection from Elements, False Life, Vampiric Touch, Bear's Endurance, Cat's Grace, Spell Resistance, depending on how high in level we want to go).
Another example, for the Fighter:
The Druid has only 3/4 BAB. But, he can use wild shape to get a form that grants him a strength score 8 or more points higher. That would compensate for 4 points of BAB right there, which requires about Level 15 for the Fighter to actually be better. he many not get the extra attacks from BAB the Fighter gets, but he may get a Claw/Claw/Bite Routine that is just as good (in fact, he's likely to be able to get that and make 3 attacks while the Fighter is still stuck with one or maybe two). And he has an animal companion with similar stats.
