Can roaches harm spiders in the same way as crickets when the T's molt?

Yes some do like lobster roaches but some don't I don't know what specie does and what doesn't Marula will know.

Not in theory?

Apart from your Forest roaches, tends to nip if its hungry or thristy.
But Roaches tend to be a saver bet than your crickets.
Its better if you remove un-eaten roaches just as you would with the crickets

But if you forget one roach and your tarantula moults will be fine!

Two of my friends lost there T's due to crickets and roaches, hence some species do. just my 2 cents

Ive never had a death of a T in this way!?!?

I have also not had any problems with any species of roach and molting T's