Wire interference with many inputs

[PaulRB]

@loveofsparks

Each button has to be wired to an input on a shift register(74hc165).

It doesn't have to be wired that way. A matrix is more normal.

@loveofsparks

Will there be too much interference in my keyboard leading to false button presses?

No. There might be interference if the enamel is old and cracked and allows shorts.