If I were to end my membership would my account still have member access until the renew date? Or do I go back to free to play the second I cancel my membership
You will still get all the time that you've paid for but as soon as it runs out it will abruptly stop. If your backpack has more items than a non-member can hold it will show as over and you won't lose any items...but you will need to move or sell stuff before you can pick up anything else or buy anything. Same for your friend list, if it's more than can be held then you won't lose any but you won't be able to add more without clearing enough space to put it below the new max.
If I were to end my membership would my account still have member access until the renew date? Or do I go back to free to play the second I cancel my membership
You will have a membership until it is out of "time". You will be moved to free play until you renew it again. -Alia SparkleGrove