Yes, this is great fun. I have a few paper designs of my own in a similar spirit and if you look around you'll find many existing projects.

However the "Min-T" name to me implies a higher ambition than "just" implementing a transistor computer. True minimalism requires exacting definitions and metrics. That could be pretty interesting, but keeping memory outside the definition is in a sense cheating as [the size and speed of] random access memory was a key differentiators between early computers (ENIAC era).

Essentially, this design would be facing the same constraints as _early_ computers, so I would expect the solution to look similar: micro-coded bit-serial design, Rope memory for ROM, and core memory for "ram". I'd look to the HP-1900A for inspiration.