Well, after some fabulous input from runer, I have ideas for tons of different instructions and registers. The opcode table is still far from complete, but I can explain the registers:
A - the primary arithmetic register. Used in tons of instructions involving math and logic. 4 bit.
B - fulfills the role of A, less instructions support it, but its good for when A is tied up. 4 bit.
C - General use register, connected closely to the O output register for quicker transport of values for shipping. 4 bit.
D - General use register, connected closely to the I input register for quicker transport of values in shipping. 4 bit.
E - general use register, can be used to complement other registers to make 8 bit values. 4 bit.
F - flag register -- includes the C, Z, N bit flags and another general use bit used in more complex instructions. 4 bit.
G - (proposed, unsure if I'll keep it) includes more flags such as parity/overflow, and a few extra bits for really complex instructions. 4 bit.
I - input register, directly deals with the input received from a port in 4 wire form, transfers data quickly to D and slower to other registers. 4 bit.
O - output register, directly deals without the output sent out to a port in 4 wire form, transfers data quickly to C and slower to other registers. 4 bit.
PC$ - the program counter register, determines where in a 2048 bit program the instructions are to be read from. 8 bit.
PG$ - the page counter register, determines what page of a 256 page (each page 2048 bits) program instructions are to be read from. Used in calculations and for easy management of pages without many ports -- however it relies on a port to actually swap pages. 8 bit.
N - the frequency register. Directly deals with the speed at which a program can run. The higher the number, the slower the program goes. 4 bit.
U8 - no use specified 8 bit register.
U16 - no use specified 16 bit register.
U32 - no use specified 32 bit register.
U64 - no use specified 64 bit register.
The no use ones can be accessed with a few more complex instructions, and can be used if you wanna use large numbers for some unknown reason. Keep in mind, these would be very slow (unlike the other less used registers, which are really fast -- these are accessed in a different way than the others due to their size, with exception of A8 being connected like PC$ (fast) and PG$ (medium fast))
Edit: I just realized I should have some more, but I'm sure people will point out things like a double word one like HL and an offset one. Give any suggestions
Edit2: and maybe another more general use one or two?