2. The spacing of the leds are pre-determined and are used for distance tracking and such. To alter them would alter how the games play somewhat. That isn't necessarily a bad thing BUT understand that if you were to spread the ir leds further apart you would have to stand even further back from the tv. So spacing them out is not going to solve your problem.
Not *entirely* true. Some of the wireless sensor bars spread out the LEDs, at least a little, to increase the playing range.
Make sure that the sensor bar extends at least 1/4" beyond whatever it is sitting on.
Try the Ultra Sensor Bar. I have it and it works quite well, though it will go through "AA"s like they are going out of style, if you don't turn it off when you're done. It has an auto shut-off, but it takes 2 hours... (Link below) Reasonably priced. $15 at Walmart. $20 everywhere else.
One thing you can try if you buy the above product: Stack the original on top of the wireless bar. This worked to help stabilize the cursor on my Wii. (Must be directly on top, not just above the other.)
Make sure that the bar is not on a reflective surface. This (in combination with lighting) can disrupt the signal from the bar.
Adjust the sensor bar sensitivity settings in the Wii's "settings" menu.
Give it some time. It didn't originally work on my 55" setup, but after a little while (and some work) it started to work a lot better.