The engine note is in a cold state. That means the head is cold, has to heat up to expand the fuel.
Again, this is a lot of condensed fuel droplets and not a mist when warm, where it would burn more efficiently and that engine note changes once it is warmed up and then sounds normal, right?
You can take off as soon as the oil pressure light goes out. Usually, I take off way before the starter motor stops spinning. In fact, when it's cold, I keep the starter moving so I do not stall on the clutch release. Then again, I putt slow down the street at about 1,900 rpm until the cylinder warms up. You do not want to haul butt, where the pistons expand faster than the barrel. That is a seized piston on the cylinder wall. So the trick is low rpm on the leave from the garage.
That is where the ECU sets the, 'morning map' to a rich set. This also ratchets the air box to open with more air because the map is fat rich and the proportion is matched, so the vent or the throttle more or less is pushed open a touch. Also, the tach/speedo needles swing back to zero so as to be accurate on the key fob move.
I'm going to take a guess at this one. Sounds strange, but my pitch on this is the cold condensed air in the tube. Once the heat expands, it acts like a balloon where you are more bouncing the now hot air caused by friction to expand, which causes the forks [air] to expand, and have less of a dive when warm.
Definitely! The break-in oil sort of flushes out the debris that was floating in threaded holes, unless they dip the post-machined cases in a sonic-bath to dislodge the machined materials during production. Either way, the break-in of the moving parts can sheer the minute material off rolling parts, get sucked up into the oil pump. The oil pump blades crush that debris, cause the pump to score. The debris is now floating in the bearings under pressure. The crank bearing inserts are soft aluminum and will embed that debris rather than score the parts. So to keep the engine clean from that contamination, you need to flush that oil out with the crap-o-la on a new bike so it lasts for a long time. Thus, the early dump of the oil.