Vary the ferts!!! One fert ain't gonna give you all needed
A point on maples and ferts: its better to use less than more as you do *not* want to get outstanding growth - the internodes will become too long too easily. I just casually fert my Acers with lowish N until late summer then go 'normal' so it can harden normally for dormancy. I tried two different sets of trees (on palmatums, tataricums, rubrums, & truncatum, fwiw) and gave one group regular N and other one low N (N = Nitrogen obviously) to see how much difference and was not surprised. I am now giving away my regular N plants as the internodes are two inches or more on average w/ the other ones sometimes having internodes stacked on top of each other (perfect!)... Just something to think about
A few A rubrum are about 4-5' tall with longish nodes whilst the usable trunks are more like 6" to 2-3' at most with nice low branchings here and there... Huge differences from different ways of growing them out.
I see way too much 'thinking'/dreaming here and less focus on basics-of-care. It takes years of basic to get to where 'fancy' comes into play, and if basics were ignored, there will be no 'fancy' time, right?? I almost bit my tongue when I read about buying the Miracle-Gro soil - augh!!! So much to learn... I *highly* suggest starting at www.evergreengardenworks.com/articles.htm and fully understanding the concepts Brent so thoroughly covers. If ya grasp the things there, books become almost irrelevant as they only present same info (usually) in more verbose manners, IMO. Just my opinion, though...
Bonsai can be done dirt-cheap (pun intended) if the technical stuff is understood
This last Fall, I started a few hundred seed of numerous species and now have over 230 potensai to play with (and bury rootballs for winter - ugh!!!)...and have spent less than $50 in toto on supplies/calcined clay from Lowes hardware. Cost of pots is not included in that, LOL. Too bad I cannot buy 'time' at the stores as I ain't got much of *that* after watering and fussing on so many pots