couple things i need help with if anyone can help

[nissankid89 240]

for one my tail lights wont turn off so when ever i park my car i have to take the battery off. would anyone know what thats from?

another thing is my car idels kind of rough and will stay cooler when im on streets but when i get on the freeway it starts to get hot but not over heat i hear the ka have heating problems but im just seeing if anyone can help me outits a 89 240 sohc