Playing as Teemo:
Q - The blind doesn't apply to the first attack after the dart impacts, if the attack was animating before the blind applies. This leads to situations where you lose a close duel to a "blinded" auto attack.
Blind doesn't stop all skills that are glorified auto attacks, only some.
W- Very old feeling skill. No scaling. Doesn't feel impactful. I'm not arguing it's not strong enough or balanced.
E-Can't be toggled, which occasionally steals camps, minions, etc.
R-This skill feels entirely different at level 11 than 6. The scaling range to toss allows for interesting play later but it almost feels like a different skill after the second rank. A buff to this was done previously but it's still substantial.
Playing against Teemo:
Q- A very unique CC(now) that arguably isn't pronounced enough, although it's getting better every time they edit visuals. Last patch it finally doesn't look like a normal auto.
R- The click area of the shroom is only the shroom, and quite small compared to the trip radius. In high tension situations clearing visible shrooms can still be a gamble if someone makes a slight misclick.
Feel free to add to or dispute my list.