You also need to consider that on-chain tx's would be cheaper. I presume that you could still do direct payment on-chain for

single once off transactions, if you wanted to. The network will be less congested, because most micro payments will be done

off-chain. This will make single once off transactions much cheaper. {Can someone verify if I understand this correctly?} IF

single on-chain tx's is not possible, then I am with you on that.  

Edit : It is also likely that you can piggy back off an existing payment channel that are open.