Per the OP, there exists a deity who is merciful, who cares enough about our wellbeing to involve himself in the minutiae of the seasons and rains, and who has committed himself to wooing us back into a dependant relationship.
Such a being would not, in all his omniscience and omnipotence, stand idly by while a five-year-old girl is gang raped. If it did, it would violate the terms of the OP: it would not be merciful, and/or caring, and/or extant.
What would evidence of design be?
It's hard to give an exhaustive answer to such a general question. Biological systems that
don't look jury-rigged together from other pieces would be a good place to start - human eyes wouldn't be upside down, the giraffe's laryngeal nerve wouldn't go all the down its neck only to go all the way back up. A designer would never create aquatic animals with
lungs of all things. He'd also reuse designs, leading to a distribution of features that
doesn't fall into a nested hierarchy - instead of putting fur on everything that has a placenta and on nothing that doesn't (give or take monotremes and things), he'd put fur on things that it made sense to put fur .
Some say that it is. I realize it's not for you. But if human beings have been exiled from the presence of God why would you expect his existence to be plain?
Yes. Per the OP, God has committed himself to wooing us back into a dependant relationship with him. The most obvious first step would be to demonstrate his own existence - if you want to woo someone who doesn't even know you exist, then onus is more or less on you to make the first move.
God has spoken thusly yet schism is rampant. Why would you expect perfect harmony among human beings if each believed that they were a god?
Since humans clearly don't believe that, your question is moot.
Do you like planet earth?
Yes, but I think it's a ridiculous place for an all-powerful being to decide to create life. God's decision to sit us on the cracked shell of a cooling rock has killed millions through earthquakes and tsunamis.