Yes, it will result in strange random behavior like value shifting on analogRead.Will it cause damage? No, probably not. Personally, I like when my circuits work reliably. We seem to disagree on that point.
I'm not sure what you mean by "reliable".
Because that's what my question is about: since everything is working well right now, will it be reliable in the long run?
but you also say that it "probably" won't damage the microcontroller
Will my Arduino eventually "explode"