I need to remove "find my iphone" from my device to utilize my warranty. I've read that I need to remove my device from icloud to do that. If I remove it from my icloud account, will I be able to still access all my info and transfer it to my new phone?
Do you have two-factor authentication turned on for your Apple ID? If you do, be sure that you have another trusted phone number; it can be any phone number you have access to including a friend or relative's Android phone or even a landline. Another trusted device will work as well, but having another trusted phone number is still a good idea. See: Two-factor authentication for Apple ID - Apple Support
If you have that covered, you will be able to use an iCloud Backup from your old phone to setup a new one and you will be able to sync any synced data (e.g., iCloud Photos, Contacts) etc to the new phone.
Yes, you can. Removing the device from iCloud does not remove your content from iCloud. That content would still be there, and accessible when you log the new device into that iCloud ID.
removing my device from icloud
