KarinsDad said:
...There should be a failure chance for all activities, especially in the chaos of combat....
That, right there, is a fundamental misconception of the D&D game. Only attack rolls and saving throws ALWAYS have a chance of failure - or success, for that matter.
Skill checks can automatically fail (or succeed) if the PC's modifier too low (or high enough) for the skill activity being attempted.
That's a fundamental concept for 3.5 D&D.
If you don't like it, well, you don't have to play that way in your games, but that's how the rules are written.
On the other hand, there are indeed times when "aid another" will not work. The rules tell us when that is - primarily "you can’t aid another to grant a bonus to a task that your character couldn’t achieve alone." This certainly could be read to say that if the task requires a DC 35 and you can't possibly achieve that, then you also can't help to get someone else's score that high because there is no way you could do the task alone. This handles the situation that seems to concern you about how an expert won't be helped by a rank amateur.
There is also a judgment call on whether "a character’s help won’t be beneficial" or how many characters can actually help. For example, the solo singer who gets prompts from someone in the audience as discussed previously. That might work just fine on aid another, but probably only one character can help - multiple characters won't matter because you can only really get your cues from one at a time. That's a judgment call.
Mostly, though, at least one character should be able to try and help unless it really defies all reasonable suspension of belief that it might be possible (or, of course, they could not do the task alone - as described above).