This is a good question and this should continue to be an interesting thread.
I don’t know of one, singular tool that can do everything you mentioned without having to basically doing the grunt work to roll your own (e.g., with a RPi or an MCU). But, there are some relatively inexpensive tools that, taken together, will cover much of what you listed.
You can do an awful lot with the ST-Link V3 Set. Unlike the V2, it’s waaay more than just USB to JTAG/SWD. SPI, serial x 2, I2C and CAN are all included and are easy to work with, not to mention scripting of GPIO using ST’s API. I find myself using it fairly often without an ST part in sight.
Note: for CAN on the V3 Set, you may need a level shifter/line driver for full functionality. YMMV, depending on the target’s power rails and whatnot. However, as it happens, cheap CAN transceivers are readily available. I have a couple, but as it turns out, I never ended up using them because I picked up a…
Peak PCAN, which is drop-dead simple and not _too expensive.
I went from zero to being fairly productive with the PCAN and its free/included PCAN View software in ~15 minutes. I haven’t needed anything beyond that tool, but there is a paid version that allows for scripting of CAN exchanges, including precise timing.
I work with someone who prefers the paid version. He does much more regression testing. So, I suppose that makes sense.
Another poster mentioned the Analog Discovery. That’s most certainly worth comparing against your requirements. It’s a Swiss Army tool like the V3 Set, but with a different focus.
Any list like this would not be complete without making at least passing mention of the powerful Saleae Logic Pro (personally, I’m not much of a fan of the base, non-Pro model). It’s definitely not cheap and it can’t be used for transmitting, but what it does, it does almost magically well. It’s an extremely capable logic analyzer with respectable analog abilities as well (±10V). Given that its sampling and resolution are pretty decent and that both the digital and analog signals (including mixed) can be recorded and analyzed offline, it can go beyond what even a good scope can do, in many - but certainly not all - practical use cases. That said, for less demanding applications, the Analog Discovery may be all you ever need and it’s roughly 1/7th the cost of the Saleae, IIRC.
Edit: I read back through the thread and see that I missed the earlier mention of the Saleae. I left the above paragraph in place, in the hopes that it still adds to the picture.