Even if you find way to pay full node which are very difficult to abuse and without locking big amount of Bitcoin, it won't solve block size controversy.
Without changing total bitcoin supply, each node only get very small amount of Bitcoin (which already mentioned above) and it won't cover cost of running full node.
Indeed. Bitnode used to implement a lottery system which rewards roughly $10 to a few selected winners once a week/month. There were hundreds of nodes and it was still when the blockchain was still fairly small.
Did it really incentivise that many people to create a Bitcoin Node? Not really, the result was fairly consistent and it didn't really increase the nodes substantially. It was paid for fully by them and it was barely enough to cover a month off fees. If it was any more attractive, I bet someone would've found a way to spoof their nodes and trick their crawler.