Hello Ally ...
I tend to agree somewhat that "Mystical" definately has less negative connotation attached to it .... but ... I have to point out something here, which is quite ironic ....
The term ‘mysticism,’ comes from the Greek μυω, meaning “to conceal.” In the Hellenistic world, ‘mystical’ referred to “secret” religious rituals, which, in all logic, should make us associate it with black masses and evil ceremonies, moreso than the word "Occult" ....
So, could it not be ... and this is maybe a long shot but .... perhaps somewhere in lexicon, language and pronounciation ... the human race decided that ... upon listening to the two words, ie. the ring it produces in the ear ..... the tone of the letter combination, the open and closed sounds they make when we say the words and the duration, itself, of the words, when they are pronounced ... were all denominating factors in deciding which sounds more pleasant ... and, therefore, misconstrued meanings were given on the basis of sound?
If you read the words out loud to yourself ....
Occult = short ... dull ... dark sound ....
Mysticism = long .... open ... happy .... almost sung type word ...
Is this why we would prefer to accept mysticism as a less negative practice, when in fact it, possibly, carries with it worse connotations than the word occult?
Take care and best wishes
V.