Firstly you should not be ashamed of working at Starbucks (if that is what you meant) If it was not for them we would not have a job and Coffee would not have such a big profile as it does, they have done some good!!! Plus it pays your way and you get to make coffee =)

Ok...They say you can leave it for max of '2' minutes but that is crap!!! Like you said the espresso goes black and loses the creme, a good espresso as we all know has a leopardy creme which creates latte art and a ring around cappuccinos when adding milk. Like leaving ground coffee out for too long it can go stale and bitter, and in this case cold...so ideally what i do is fill my milk jug then do my espresso and immediately do my milk. The espresso should take 20-30 seconds enough time to nearly finish milk. Then pour when milk is mixed etc...Customer service at it's best, providing good coffee quickly. Ideally you should be pouring your milk into an espresso that is still hot with plenty of creme. If it starts to fade away then pour it away and start again!!! Practice makes perfect...I think 10 seconds is fine but not the end of the world of over that time. I hope thats ok? As long as it is a good tasting coffee you should be fine!!!! Just dont leave it for minutes that alot of cafes tend to do!!!! yuck!!!

take care xx

Seriously... steam the milk first.
The milk will not be compromised and the shot will be protected. I've said it before.

i have silvia, which is not really for milk drinks.....
I pull my double first, then a short cleaning flush, grind for second shot, pull shot, get ready to steam etc.
My shot sits somewhere between 5-10 minutes (haven't measured) before I put the milk in. I use fresh beans from hasbean and there is still crema when I pour the milk.

My total routine for creating two cappas and getting everything cleaned up for the next time is about 15 minutes.