Question 1 - No, honest does not target.... So nothing to negate
Question 2 - No, Solemn cannot negate something that comes of an effect.
E.g. You can solemn monster reborn, but if you let monster reborn go through, and it calls MOBC, you cannot solemn MOBC.
Furtheremore, Valhalla is already on the field, so nope, you cant negate that as well...