My canon belief is that Leia had a sense there was a connection to Luke (that she references to “always knowing”, which can mean a lot more than just about Luke) after she heard his calling out to her from Cloud CIty. This would be long after both kisses, and both of them were pretty innocent within context anyway.

As for Anakin, he was the most powerful at that point. We see this by the measurements (yeah, I hate that Lucas defined what was meant to be mystical), we see this by the later results in him matching up with other more experienced Jedi, and we see him as a severely crippled Vader who is still devastating to anyone. Anakin weakness wasn’t his abilities, but his lack of patience and control, thanks to maybe his age if Yoda was right, but the lack of the Council aiding what training could be done, and also fueling his fears and anger later.

Luke could be more powerful. We never see his peak level except in cases like in The Mandalorian. That Luke is Anakin-level but with control of his actions.