Does iMessage take up iCloud Storage Space? If I send/receive iMessages, or photos and/or videos through iMessage, will those iMessages take up my iCloud storage space?

I am not talking about iCloud backups. I'm asking that if I do not backup my phone using iCloud, will iMessages still take up iCloud storage space?
No, iMessage and iCloud are (for all intents and purposes) unrelated services. Photos and videos sent or received through iMessage are only stored on Apple's servers long enough to deliver them to all devices you have registered, or seven days, whichever occurs first.