The rub sounds good with two caveats. The first is more niggling than anything else. That is, most good poultry rubs have some herb to them. The "big three" with bird are thyme, sage, and rosemary. Go easy with all of them, especially rosemary. The second is more along the way of general advice as you move from home cook to cook, i.e., from Joe to pro. Be careful with cayenne and other hot peppers. If you're trying to balance the sweet with hot, rather than hot and sour or just sour, you like a lot more heat than a considerable percentage of the rest of Charlotte. Too hot is a problem which cannot be easily fixed once the seasoning is in the food.
The key to fixing your glaze is to cut it with an alcohol or vinegar, apply to the bird on the grill, and grill very briefly until set. You don't want to burn the glaze because it will become very bitter. But you do want a little char to cut the sweet. It takes attention. For what it's worth, I was very successful with something similar. Specifically, lime marmalade cut with tequila; and fwiw the chicken was brined in a lime/tequila mix.
To cut the wininess, you need to cook the wine signifcantly longer, but that would wreck the chicken; cut the wine with a little stock, a very good idea; switch to a mellower wine like sherry, dry marsala, or madeira, but they don't go well with pepper; and/or use a butter finish.
Otherwise, tThis sounds very much like what the employer already does but with a little originality. Trust your guests.
The only suggestion I have is slightly technical. Given the nature of the job application and of the sauce itself, use some butter in your pan along with the olive oil. You want the blend to be around 2 parts butter to 1 part oil. The tricky part is getting the heat and timing right. Ideally, the chicken will go in the pan just as the butter foam starts to subside; and the chicken will be just cooked through just as the milk solids toast and the butter becomes fragrant. The timing is a pro/Joe thing, over a medium-high to high flame. If you can manage not to burn the butter several times in a row before trying it as a demo.
I've got personal issues with calling a cream sauce carbonara, but it's pretty common here in the US, so tough for me.
Some extraneous thoughts:
I'm familiar with Grey's chicken and really dislike it both as something to eat myself, or as a choice for a demo for a number of reasons which I won't go into. I bring it up only to illustrate that tastes differ quite a bit, and my experience leads me to believe that Grey's advice is every bit as good as anything I have to offer.
You can do chicken dark meat straight across for a lot of breast applications, but paillard/escalope requires some dexterity with a knife. If you're good at boning out leg quarters, and can't skin, bone and flatten a thigh without tearing it up too much, dark meat is something to think about. I'm not sure how familiar you are with the process, but the thigh bone is very close to the surface of the meat, so when the bone is removed it leaves a very thin and fragile section, and the leg is a bit complicated. You can make paillard, escalope, schnitzel and so on, but it's not easy.
From a catering standpoint, dark meat holds up to a chaffer much better. On the other hand, customers -- especially women -- prefer to see breast. I'm told the equation is, "half a chicken breast now = cake later." The reality that there isn't really that much of a fat/calorie difference between skinless thigh and breast is not as important as the emotional connotations. We don't eat with out degrees, afterall.
Thus, dark meat is usually reserved for Asian applications where it's largely hidden, like Thai coconut soup (Tom Kha Gai), fried rice, kung pao; and and long cooked braise/stews with dark sauces like etouffe, marsala, and Marengo. Or for the specifically hearty, like barbecue.
In the case of an event caterer, a wedding caterer especially, chicken is often the alternative to beef -- and is chosen, partly at least, to be "lighter." So breast is what you see and what you need to master. If you have the opportunity to develop your own recipes, brining can be very helpful.