Can candlelight be in plural contrarily to light? I am wondering if candlelight can be plural when there is many candles contrarily to light, which is an uncountable word. What's the consensus on this?
Not really, no.
In general, "candlelight" is an uncountable noun, just like "light" is. If you're reading a book by candlelight, it doesn't matter how many candles are generating the light.
However, there is the unit of measurement called "candelas" which measures the brightness of light (in general), and which is approximately equal to the brightness of a single candle's light. There's also the obsolete unit of luminous intensity called "candlepower" (plural form also being "candlepower", as in "this flashlight has a brightness of 50 candlepower").
No. To make a lot of light you can have many "lights" (objects that emit light). So the word "light" can be both countable and non-countable, with related but different meaning.
But to make a lot of candlelight, you would have many candles. The countable object is not "a candlelight", it is "a candle".