To #1, I get on every day. And yes, the more you grow the more interested you get in this game
2nd, you can loot money and tech on a nation. You can't take over a nation nor can you lose yours, you can attack a nation until he has 0 infrastructure, he's pretty much done after that. You can attack a nation 2 times a day with regular soldiers, there are other ways of attacking though. If you attack someone, that person will get a message about it, and yeah if they know they're in a war, they will see it coming.
Hope that helps