My lead melodies usually start as a piano. Just because it's a "neutral" sound and if I don't like something about the melody on piano, I probably won't like it with some amazing synth noise.

After I like it, I pull up Synthmaster, Massive, or Hybrid and start flipping through presets. Once I find one that sounds half-decent, I modify it to fit the track better (remove effects, shorten the decay, add filtering, etc.)

I do almost all mixing on monitors, although I switch between two sets of monitors and some cheap speakers.

I think headphones are needed, though -- nothing else lets me listen through a track and find really quiet mistakes like clicks, dropouts, and so on. (I tend to monitor at low volumes, I suppose if I cranked up the monitors I might catch those too.)

Any source of true white noise will sound the same as any other source. But generally white noise in EDM tracks isn't really white noise -- it's filtered to sound better. You almost always want to take some of the lows out (maybe cut at 200Hz?) and some of the highs (8K?).  Depends on what you're using it for, but for example with risers I run them through an EQ to high-pass at 200Hz, then a filter that sweeps from 200Hz to somewhere around 6-8K at its peak.

It's also highly dependent on what you're mixing it with. White noise layered with a snare should only include frequencies the snare doesn't already have. Sometimes I mix a bit of noise with a pad, and in that case I usually use a bandpass filter to only let a certain range through.

Yeah, sometimes I catch myself thinking "I don't like this particular sound/melody/loop. I'll just turn the volume down on it and let it be a background thing."

If it doesn't add something GOOD to the track... it shouldn't be there.

Agreed. I spent 20 years making music without knowing any music theory, and then I took guitar lessons (including theory) for a few years. I came up with some good melodies before, and some good ones after. The cool thing about knowing some theory, though, is that I can tell why something sounds good or bad. Before I would struggle with chords for weeks, knowing (because I listen to lots of music) that something was wrong with one of them. Now I take one look and say "That third chord has a minor 7th in it when the scale should have a major 7th."

I can also do way more complicated things now. I used to stick to 2 chords per song, now I can make a good 8-chord sequence and change it up sometimes.

I can still break the rules when I want to.  I can promise you learning theory didn't make me less creative...

Well, "overproduced" isn't something I say about electronic music much, but there are things like "Simply Being Loved" by BT where he was literally trying to break the record for most audio edits used in a song... the vocals are so glitched it's technically impressive but definitely loses some of the "hook" the vocals would have had.

For my own music, the thing I watch out for is if I'm working harder and harder to "fix" a track I don't like. It ends up overworked and muddy but the fundamental problem is still there. So I try to make sure I have some good melodies, chords, and sounds that work together before I start adding effects.

I have it and like it -- haven't reached for it lately, but I should again. It's very good for basses and definitely has its own sound.