Haha...QUESTIONS over questions! ;D
Well, take a closer look at the different sections on each synth. But the first one you should have a look at is...
(my god I'm writing a manual, here, haha...but isn't there one already!?! Yes there is, but anyway...)
"general options" (button on the right upper corner of the synth).
In order of importance I'm listing what you can control there:
- the speed of changes that can happen to the sound.
(attack) - as you trigger (press down) a note, the synth advances through all the "drawn" envelopes at that speed.
(decay) - as you release the note it finishes going through those envelopes at that speed.
(a.loop (arpeggio loop)) - on/off toggle. If it's turned on it loops through your arpeggio sequence (default setting). If you turn it off it only runs through it once!
(arp spd (arpeggio speed)) - the speed by which it runs through your arpeggio sequence.
(mono) - on/off
(sld) - it's important to mention those together, since this affects strongly the kind of behavior of your mono mode. It sucks, since you either slide from note to note or it always gets fully retriggered, sending the sound through the entire envelope from the start. Bad, bad...pfuiii! But well.
(vd - vibrato depth) - how strong swings the vibrato around your note
(vs - vibrato speed) - how fast
(del - delay) - how long before vibrato or slide kicks in (questionable to hook them together, but it's alright.)
(ss - slight speed and direction) - how fast does the sound slide down or up (I'm not fanatic with the level of control, but it does the trick on some percussions and occasional effects)
Anyway, to get to your questions more directly, go to the second column of 4 buttons. It turns your adjustment window black with a few pixels in yellow followed by a vertical white line. Those are your arpeggio notes. With your left mouse click you can change the note of each step. With your right mouse button you can actually turn a note off completely!
Each of the oscillators has its own arpeggio sequence. This allows you to give them different behaviors. With arpeggio loop turned OFF you can then for example have an oscillator only be on for one step and then go off. That's what I did to the noise.
The other way to go about it is to adjust the volume envelope, the first 4 button row. You can ramp down the volume of the noise before the other oscillators. A finer control for sure, but watch your looping range.
I recommend looking at the manual/tutorials a bit more closely. I would imagine that DrPetter was putting in all the important info to get started. But relax a little, take your time. Don't rush!
My eureka moment were the attack- / decay- knobs. Without knowing how this most basic part of the concept, all experiments were futile!
Again, take your time and don't give up. The moment you get it, a whole world of sound design and music making is opening up to you. And once DrPetter is in the mood and doesn't mind for us to look at some of the stuff together and have a chance to experiment with new possibilities, there may well end up being next to no limit for what you can do with this lil' piece of brilliant ingenuity!

(forgive me, if it sounds a little arrogant, but I honestly just know what I know already and have a fairly reliable hunch that I'm aware of some very powerful innovations, particularely in regards to sound-design!)