I don't really think any of your hitchhikers are bad. The worms come with the LR
and can be a good thing depending on what they are. Bristle stars are a good thing too. It rare that u get the mean fish-eating kind. And those hydroids ate usually not bad either.
I personally love hitchhikers and so far never had anything bad. Does it happen? YES, but rarely. I once heard of a guy who had an octopus hitchhiker and loved him!
Patience is important in this hobby. I have more than 1000 times just wanted to scream, and lost many many hours of sleep over it
Hitchhikers happen and usually they are fun
aphasia is easy to get rid of, worms are good, and those hydroids aren't bad either.
Nobody wants to get stung by their tank, but sooner or later one of your fishies will try to bite you anyways
Just take the good with the bad and don't start over... Just go with it
Huma is prolly sitting at home thinking: "there ahe goes again with her sit-back-and-let-it-do-it's-own-thing talk"