No less honest than George the Elder claiming a hotel room for his address in Texas during his presidency. He spent more time in Maine than Texas.
This is a long-standing tradition among DC officials.
Laws are made as boundries. Going to the edge of the boundry is NOT breaking the law, nor is it in any way shady or unscrupulous. I don't know why people think it is...
The only way this would be illegal is if Rove voted in both places.
Yes, at least he owns a house or two in Texas. I don't see anything wrong with this. Like you say, a rental house on some property is much more substantial than a hotel room.