This looks good to me.
In general we got to keep in mind that 44 is mixed here pre and post. So as long as you dont always/never call pre and dont always/never start bluffing every small PP, you will have a good mix i guess.
So these small pairs are good candidates to simply check down from the flop on as they have indeed some SDV or they make up for a good triple barrel bluffs on a save runout.

This is mainly due to their good unblocking effect of Villains XC/XC/XF range.

So interestingly 44 is a much better candidate for this move in this spot than 9T or QT for instance as hands like 99//TT/89s could be part of a range that folds to 3 barrels.

Just dont make the mistake to randomly bet flop and/or turn and then give up without a clue OTR!

Your play is somewhat standard/good but i think there are some underlying flaws in your thinking:
Can I starting bluff with this hand OTF after SB check?

Yoou're not bluffing - you're value betting/protecting

I'm not sure if I have too much SDV to turn my hand into a bluff.
Correct, but again, you're VBing

My plan is to barrell OTT & OTR when board is good for my range.
River barrel would be bad unless you think your opp would call his AK-type hands. You dont need to protect anymore on the river as its usually 100 / 0% equity

As played, should I bet OTT?
Yes, for reason above.

2 major things:
1. Opps at these stakes are heavily unbalanced toward weak / missed hands when they check
2. This should depend a lot on how opp plays as you will have to F vs xr so you can think about how that affects your actions. But, again, i would still bet cause of reason #1

I suggest folding 44 pre vs 3bet in fast fold but I'm a nit so you do you.

As played - he clearly had AK/AQ that check called the small flop bet and folded turn when missed. You have sdv if he tries to check down an unbalanced A/K high range, but vs a balanced player you have little sdv since they will show up with 99-TT/Jx here sometimes. Pick the line that best exploits pool ranges in these spots.

The tradeoff here is once you barrel off you lose your SD value. So I think betting turn for the same small sizing as the flop accomplishes the same thing while leaving you more options on the river for either checking back and retaining some sdv in a smaller pot or bluffing again when river card is good for you. Because right now it looks like you are getting too many folds in this spot with this sizing, so the best hands with this line are your pure bluffs/floats as oppose to low pairs.