I've found that many LEDS in parallel use less current than one.
Try to figure that out.
I used an DC ammeter & was amazed that as I piled them up in parallel the current stayed about the same.
I have not seen really large White LEDS but as you cluster them they are too bright to look at.
The lensing is very important.
I have not used pulsed width modulation as a control for these however I would try a rheostat or go with a DMX interface. That is another whole engineering class.
We've been experimenting with these LEDs & we've found OPTILED to be a good source.
I would say that LEDs are a long way to work for stage theatrical lighting but the coloured LEDs as a wash are effective.
Time will come with a combination of stronger output & the proper lensing where we might be able to replace standard lighting.