I know that 'x' is eXecutable, for scripts to be 'executable' the attribute has to be set. For directories 'executable' means something different; the ability to 'cd' into the directory in question

My question was more if executable right is also needed for 'group' and 'others', instead of only needed for 'user/owner'? Scripts/files should not have more rights granted than necessary. Ok it's nothing security related here, it's merely for correctness.

Btw; maybe outsource the dependencies installation too in a separate script and do a test using dpkg or apt before if they are installed, otherwise download & install package(s).