Sort-of-cop: Headass, 1 bytebyte; cracked by m90

E 

E allows you to access stored variables other than the four main registers, access other code blocks, and also halt the program on a dime by trying to reach out of bounds with it (though you can still halt without it)

I'm not sure whether it is TC without it, because you can still loop / enter and exit loops with {}:;), but I feel like the lang may be too constrained to allow you to do enough. Just a gut feeling not sure.

Sort-of-cop: Headass, 1 byte

} 

On the opposite side of the coin, without matching loop brackets, there's no looping within each code block. This means you aren't able to loop through input or all of your stored variables, which makes me 90% sure that it isn't TC, since you can't store arbitrarily many variables. Looping is still possible with E, but the main registers are cleared. Additionally, variables have no upper limit, but encoding/decoding data would be hard probably.

Not a cop: Headass, 2 bytes

E} 

If all else fails, remove all loops :)