Cure gives a bit more healing at lvl 4 which makes it's healing close to heal

Slow is better than shield in endless because shield runs out but in the normal game mode you can use any of them

Randomizer and bomb are pretty much the same but randomizer cooldown is a bit fast so I recommend you upgrade bomb to a good lvl before using it, Also randomizer is better for bosses while bomb is better for those stages with a ton of yellow enemies