I think Obi-Wan believed Anakin was (literally, biologically) dead when he dropped off Luke, and that Owen would have also. And that it wasn’t until later that he learned Vader survived. It explains why they thought taking Luke there was a sane idea and more comfortably fits in with what we hear from Owen and Beru in ANH.
Yes, but the question of leaving Luke at the family homestead with his old surname is a separate issue (exacerbated by the prequels of course!). I’m talking specifically about Obi Wan’s ‘certain point of view’ which, let’s face it, just doesn’t feel right. If he’d said in ANH “Vader hunted the Jedi down, your father died in the purge” or something similar, it might make more sense. My contention is that Obi should’ve owned that original lie. It would be much more plausible if he had actually lied for a good reason - namely an agreement with Owen for the benefit of Luke. The whole ‘certain point of view’ thing seems way too shifty, but simply going with “I promised your uncle I would say Anakin had been murdered” is very plausible and guards against any erosion of Obi Wan’s nobility. It would also lend some depth to Owen’s position as someone who genuinely cared for Luke’s well-being.