I've actually done this, albeit with less stuff overall, multiple times.
Here's my experience and for the OP and regarding your points, that I think are very valid.
1. I had all my data on mirrored RAID and so I just had half my drives in the checked baggage and took the other half into my carry-on. FWIW, if you have 2TB, that's not a lot. I don't know how old your drives are but at current hard drive size I bet you only have one 2TB drive there if you're not already running a RAID, else two. I had four drives total. Someone might ask if you travel with 20 drives ;) Since "a truckload of tapes" has a much higher bandwidth than any internet connection, even today, I bet there's a lot more travel with "hardware" than one might think. Like you say, this applies to lawful travel.
2. Nobody cared. I wasn't asked about my carry-on at all. We had multiple laptops and a few hard drives, CDs, USB keys, CPU, RAM. I never got a "citation" about the checked baggage either. I would say that unfortunately here we do have to mention "racial profiling" i.e. YMMV depending on where exactly you travel and whether you're a visible minority in any of the checkpoints you go through.
3. I guess it depends on the exact make up and volume. Do you have 10 SD cards? Nobody cares, people have lots of devices that use these suckers. DSLR Camera? It's normal to have at least like 4 SD cards just for that. FWIW, a few times I had the CPU and RAM in my laptop bag but decided I'd buy a new case and motherboard at the new location for example.
4. This! Even the time when we shipped everything, because the container would take "forever" vs. us flying, CPU, RAM and hard drives still went with us, sold the motherboard and bought a new one on arrival and ran it all "open air" until the server case arrived a few weeks later by shipping container. Nobody blinked an eye anywhere.
5. I think this can't be overstated. Be nice. Be courteous. Be honest. For the above tech stuff we were never asked. I bet they see this all the time in their scanner. But we have been pulled aside to open one of our carry-ons because they couldn't figure out what was in there via the x-ray scanner. So we had to explain to them why it was full of old match box cars, playmobil and Lego!
Anecdote: I have been asked to boot a laptop I was carrying once. That was when we were visiting the parliament in Ottawa. I don't remember why I had the laptop with me, probably because I didn't want to leave it in a cheap motel lol! I never thought about it, until they told me to boot it up and I got really concerned, because it had no Windows on it, just Linux and I didn't have graphical boot (i.e. no nice logo or anything) and it booted straight to command line login. No issues. You might have a different experience visiting the US capitol ;)