Dumbledore always let Harry try his strengths. But in desperate times as in Deathly Hallows, is it right for him to have kept mum? During their exile, Harry asks Phineas Nigellus if he could bring him Dumbledore. But surely Dumbledore, though dead by then, but being an extremely powerful wizard, could have devised numerous ways to communicate with Harry!
At the very end of Deathly Hallows, after Voldemort is dead, we see that Harry is able to communicate to Dumbledore via his portrait regarding the resurrection stone. If he was able to do it at that time, why not much much earlier, when he was treading his path with skepticism, in thirst for the numerous truths like the Sword of Gryffindor, Dumbledore's extraordinary life, the Deathly Hallows, etc.? Wouldn't it have made everything simpler and perhaps could have brought about the death of Lord Voldemort way earlier?