Lake hotel has a lovely setting, but the hotel itself is dated and worn. Food would be your two veg, meat and spuds variety. Not a romantic getaway I would have thought. Aghadoe Heights is very very upmarket and luxurious (although not snobby)- but you will need a car. Hotel Europe is also outside Killarney, you will need a car, but also upmarket. Dunloe well outside Killarney, definitely need a car, nice but dare I say, a little snobby? Maybe just my experience. Not open all year round either so you would need to check ahead. The Great Southern in Killarney has gorgeous rooms ( very romantic ) and a hell of a facade for that grand entrance and is right in the middle of town- nice hotel. All of these are in Killarney in any case though.
Sorry in advance but I don't think a single hotel in Tralee would qualify for a romantic get away break. A break away with the kids would be great here as theres plenty to do in the town and surrounds.
Theres a really nice B&B in Dingle- Bamburys- that I would recommend. Dingle itself is the right size for a romantic getaway- plenty of scenic walks, gallerys, nice restaurants, friendly people, good pubs and good pub grub.