That mirror trick is super interesting. Thanks, NFS.

Buying lenses for full frame cameras does "future proof" your setup, if you decide to go full frame.

I would recommend an emphasis on lenses, over camera, since lenses can last through multiple camera bodies. All those EF lenses you listed are lovely, but you can get some really nice manual Nikkor AIS glass on ebay for pretty cheap, if you look for it.

Lighting and audio are very important, don't forget that.

I want this so bad, and I have no reason or use for it.

I have not, though I'm sure you could make it work. If an H2n is all you have, then use it, but if you can get your hand on a shotgun mic, boom pole, and audio recorder with XLR inputs, I would recommend that. Audio is important, and having your characters lines being heard with the focus and clarity of a shotgun mic is much better than a field recorder with two built-in speakers.

When I play a scenario like this in my head, I imagine the first two or three times of this event or series of event being played out in full. Then after that, show the character doing repeating the actions, but cut the clips a little short and shorter every time you choose to repeat it. Then, start to make the scenes go quicker, and a little louder. Almost until it's like, a frame of said thing for only an second or so.

My reasoning behind this, is that once we do things for so long repetitively, we do them quickly, and almost without effort. Muscle memory.

That's just how I envisioned the scenes you described in my head, but I suppose it only works for small short actions. Hope that helped!

Creates a spike in the audio that is easily distinguishable for audio syncing. Sometimes using programs like "PluralEyes" and those "synchronize clips" features that Ryan above me has mentioned, sometimes, when I'm in a super efficient work flow and 110% in the mode, I just do it manually. Not sure why! I suppose I like to be a little more hands on.