I don't know about spraying on a Japanese Maple, at least not in my area(Eastern Kansas, Western Missouri). It might depend on what part of the country you are in and what potential pests are out there you might be spraying for. I can't think of any that target Japanese Maples off the top of my head, maybe someone else can. Of course my potential values were all based on my area and based on supposedly healthy nursery stock, not trees being moved from some other private property to another. I did mention that the lace leafed cultivars are far more expensive than the non-lace leafed cultivars. I'd also say that 90% of the red leafed(non-lace leafed) Japanese Maples sold in much of the Eastern 1/2 of the country are indeed 'Bloodgood' or one of it's seedlings, so it and it's seedlings(which of course makes them NOT true 'Bloodgood') by far are the most widespread red leafed cultivar you will find in much of the country. I mentioned Japanese Maple nuts/aficionados/enthusiasts know probably hundreds of cultivars and can tell the minute differences between them all and could probably give a more informed opinion of the true cultivar of the tree in question, like bboy did. Many of them look so similar to me that they just kind of all merge into the same thing.

The white fluffy stuff are cottony maple scale, a sucking insect that can create plenty of drippy honey dew (like aphids). The other insects are some kind of beetle pupae, don't know what kind. They look quite a bit like ladybug pupae, but I don't know for sure what size your insects are. Mind you, your tree could have aphids, as well! Very common with maples.

You're right - that isn't much to go on! With perhaps 500 named cultivars in commercial trade and many fitting roughly that description, not to mention a few dozen more cultivars of shirasawanum and japonicum that most folks think are also J. maples, any guesses would just be a shot in the dark. Fortunately the Puget Sound area of Washington state is home to dozens of excellent nurseries, many featuring large selections of Japanese and other Asian maples. A number of public gardens and arboreta also have maple collections you can view for comparison. We have just peaked with fall color on most maples in this area and they are starting to drop leaves, so now is perhaps not the optimum time to select based just on fall color. One cultivar you may want to pursue is 'Osakazuki', which is known for stunning fall color. Pretty popular in this area, it will develop a rather horizontal branching pattern and is often sold multi-trunked or with a very low crotch. It will get quite a bit larger than 12-15' in time, ten years being rather young as J. maples go.

Expensive grafted named cultivar coming from Arbor Day seems pretty unlikely. Especially if it was free. Tree looks like a typical wild-type seedling. So it is likely to produce a small (15'-35') vase-shaped tree that will take many years to reach full size.