Why "should" there be negatives to it? Again, my goal as a DM is not to punish my players for having novel ideas.
And the "negatives" handle themselves anyway. The group would know that they won't even be able to teleport unless they can hire somebody to send them, that sneaking around probably isn't their forte, and they don't get the wizard cheat codes. If the above are necessary to achieve a goal, I say the adventure is poorly written, not just poorly run.
But that's a different discussion.
I think a different party will have different levels of difficulty with different parts of the adventure. The secret vault opening will be a major challenge to the "all paladin" party. They may have to leave, do some research and return with a magical doo-dad or a competent NPC to deal with the secret vault door. *However*, the 4 undead gardians behind the vault door - which would have been a major challenge for an average party - will be completely demolished by the all paladin party.
And I think this is perfectly ok