I wont post my food list here as its rather big - given I have a more varied community than you do - plus a few 'fussy' and 'complicated' fish - it may add to confusion.
So what id say is this - keep the smallest mouths in mind when feeding - as you have tetras - stuff like hikari micro pellets and micro wafers would be good - you can also now get small species specific flake - usually aimed at gupsters but its good for everything else.
Like humans - fish get vored of the same old food and also - if you only feed one type of flake - some fish will only eat their favourite colour flake and ignore the rest.
As for the live food - I used to think like you - but ive seen the benefits outweigh any small risk by a long way. Also - as long as you keep to decent brand name freeze dried food - you can be 99.99999% sure its safe - eg King british tubifex worms and blood worms. I also use frozen bugs (about y only regular purchase from P@H these days).
You can also buy brine shrimp flake and dried daphnia (usually targeted for marines but its fine for any fish)
The other option is grow your own (brine shrimp) I do this for the baby gupsters and all the fish love some freshly htched shrimp - even the angel fish in the main tank go nuts for them - its easy to do and you can get a starter kit for £20 that will put you on for a long while.
If you drop me a pm with your postal address - I can send you a pot of my mix I use for my gupster tank - Diana had some a while ago and i dont think it killed her fish (yet
) - it basically has a big mix of all kinds.
BTW - I hereby fess to forgetting that the spinal kink can be caused by accidents in the tank - ie decor falling onto the fish etc - rather unusual tbh but possible - one of my cherry barbs developed a back kink early on (about 2years ago now) ans she is still doing well.
If you want to introduce new foods - you could be cheeky and ask the manufactuers for free samples - a bit of fibbing helps (ie 'im starting a fish breeding business and would like to see which food works best')
You dont know if you dont try
as I said - drop me a pm and i'll get some food in the post asap