If I disable messages in iCloud storage, will I still send/receive text messages?

If you turn off Messages in iCloud on an iPhone, iPad or iPod touch, your message history will be included in a separate iCloud backup, as we mentioned above.

You can choose to turn Messages in iCloud off for just one device, or for all your devices. Any device where Messages in iCloud remains on will continue to store what you send and receive from that device in iCloud.

Yes.

You will not get them on other devices on your account.

You would have to have a lot of big attachments to save significant space.

Which means they are in iCloud messages PLUS a new backup which is twice the iCloud space.