Aode forLED Aluminium Channel 6 Pcs

How well are lights diffused? i need a very thick milky/frosted coating so you cant see the leds at all. looking for a smooth look.

can additional mounting clips be purchased seperately?

Is there an L shaped connector for creating 90 degree corners with this channel?

are there any 90 degree connectors for this? I have one strip and would like to go all the way around the room without having to cut the LED strip.