It may be a bit more apparent on the larger screen of my iPhone 7 Plus and 12" iPad Pro, but in Message in iOS 10.3.4 beta 2 getting to the special effects you mention is a two step process. Initially Message to the left of the text input screen there is a "Greater Than" arrow (>), Touching that icon brings up three icons....
  • A camera
  • A heart
  • And a graphics icon
You have to touch one of those to activate the different special features/effects you are talking about. Touch inside thr text entry field and those go away, On the iPhone If you touch inside the text field a microphone will appear at the left end of the text field to activate dictation. The microphone icon is at the right end of the field on the iPad and you have to hold it all the time you are dictating. If you start typing your message suggested emoji will appear among the suggested words below ther text entry field. Touching the emoji will replace the word you are typing with the emoji, but there again it akes a positive action on the user's part to initiate the feature.

Just be deliberate where you touch and any special effects are easy to avoid. In fact you have to be relatively intentional to bring them up. I have gotten to the point there it is usually easier and a LOT faster to dictate my message so erroneous fat fingering the keyboard is not an issue for me.

ADDENDUM 1: I think I just figured out what you were talking about and why I could not duplicate it. If you were referring to the floating balloons and other glitter that was appearing on all messages — that has already disappeared. It was a short term iOS 10.3 promotional gimmick that lasted only a few days and then self destructed. It should be long gone from your iPhone by now.

ADDENDUM 2: I know you won't be pleased to hear this and remember it is NOT official but the current thinking on the rumor sites is the popups that now appear when launching 32 bit iOS apps to the effect that you need to contact the developer and get them to update the app because Apple will be dropping support for 32 bit apps in a future release is a heads up that the iPhone 4 will not be supported in iOS 10.4.

Last edited by joemikeb; 04/15/17 02:05 PM. Reason: Addendum 1 and addendum 2

If we knew what it was we were doing, it wouldn't be called research, would it?

— Albert Einstein