If the engine is stock, there's no need to adjust VTEC crossover point.

From what I understand, the VTEC crossover point is set at a value stock where the amount of power being made by the engine, the amount of air and exhaust to go into and come out of the engine is increasing, and therefore the valves have to say open for longer. Now, when the valves are open for longer, you get what's called valve overlap.

The point is, that when VTEC crosses over to the higher profile, is when the motor requires longer duration and lift. Therefore, if you do it too early, it's making it too difficult for the motor to get the air that it requires in, and out.

E.G. If you have a straw, if it's small, it takes smaller effort to inhale / exhale, but the volume is diminished. That's great, but you can't really drink your big cup of coke through a tiny tiny straw. So, when your motor is in NON VTEC mode, it's being economical, and creating a bit of power, but once you need to get more air IN and out of the engine, you need to have longer duration.

Now for overlap, this is my understanding, and I might be wrong.
When you have really bumpy camshafts geared towards making more power N/A - they tend to have high lift and long duration. With the long duration you have long overlap. Long overlap makes the motor lose some compression seeing that the exhaust valves are open when the piston begins its compression stroke,you know, when it moves towards the head for the big bang!

So when you put in like TODA VTEC KILLER CAMS, you're better off upping your compression ratio in the engine to make the best possible power.

You DONT need a VTEC controller unless you have got NEW cams or you've upped your compression. And this is something that YOU HAVE TO do on the dyno, with a knowledgable tuner, like Adrian from Toda, or Dyno Dave, or other well known and published tuners (Adrian is in EVERY autosalon and Hot4's magazine somewhere).

Why doesn't it work setting VTEC to crossover lower? cuz you've got a lobe thats designed to work at higher rpm's running when it isnt needed. if you were to adjust it higher, you'd be choking the engine of the air it needs to burn, and when it did kick in, it'd be like a kick in the face.

As for cam timing etc, there's no point in adjusting cam timing unless you have aftermarket cams, and there's no point in adjusting the ignition unless you have built up your engine & installed cams.