Basic list of types of magical trinkets and properties

Tarnished - damage over time to user
Blessed - short duration damage shield
Ethereal - basic stat(str,etc) increase
Shinny - damage over time to user
Blighted - monsters are like you more :)

So not all of them are useless,

Flipswitch

I thought they all had random effects, just high chances of certain effects depending on the type of trinkets. I think I've gotten all kinds of effects from all of the trinkets (I have fun using them - gotta luv death by trinkets!), though your list is likely what is the dominant effect from each.

There is a Trinkets quality list on the Wiki, and yes, there is a percentage change of getting a good/bad enchantment.