This is obviously a mandatory cbet. This kind of 'villain is unlikely to have anything' line of reasoning while true is just a function of the board texture. Sure, the villain can't connect well with a 494 rainbow because... well... no one can:) That being said your check won't magically change a passive anon NL4 player into someone who's willing to turn the bottom of his range into a stab. It can only cause you to lose some value from the medium part of his range which he definitely will play passively if you allow him to do so.

As played easy game, you just missed one crucial street of value (the one that makes all the other ones exponentially bigger).

See, now that is what I came here for. No BS, just the truth of the nuts and bolts of it. Game over.

Yep definitely go with a flop cbet. Once flop checks through as played I'd like a bigger bet on the turn. You're not trying to target any low pair type hands. He will have some Qx or a draw like JT KJ that will call regardless of sizing (to a limit) and everything else will likely just fold unless you make it crazy small. I'd go something like 6bb. River bet is great. You're probably only getting called by Qx and that hand will definitely call the big bet.

Thanks very much, it's taking me a long time to get bet sizes right, they aint easy!

I absolutely agree with C-betting this flop. I have definitely seen people call these types of boards with random overcards so even if the villain has nothing it doesn't necessarily mean you will get only folds. I also agree with the larger sizing then on the turn as played. Villain is not really going to change his calling range here based on your sizing (within reason obviously) so I would be going closer to pot here. On the flip side with this hand, due to this exact reason I would generally opt for this type of sizing with our bluffs. I don't think anyone in the 4NL pool is going to be perceptive enough to notice that you have different sizings for different hand strengths in this type of spot so we can definitely get away with our bluffs cheaper this way/maximise our value with our stronger hands.

River then I like, we can maybe go a little larger though since the chances of villain folding a Q here is essentially non-existent and as you have correctly mentioned he will be folding almost everything else he can show up with here regardless of your sizing. Note though that if we had sized up on the turn the the pot would be ~20BB's so our river bet could have been for around 18BB's which would have lead to an additional profit of 7-10BB's depending on your exact sizing.

C betting is standard against a passive player who will be more inclined to get sticky and give you a full three streets of value. It's a crime to give that up on the flop.

The river doesn't have to be a big bet but if money has gone in on flop and turn then you can still make a nice EV bet offering villain irresistable odds.

Yeah, missing a lot of value here potentially with the flop check. The hand can easily be worth three streets of value, so no good reason to slowplay. This can easily be one reason why your flop cbet frequency is so low. It's not purely that you are missing cbet bluffs, but also potentially slowplaying value hands too much.