Oh this is a fun one.
Which is your favorite hole to receive?
Tough to decide just one. Toys I prefer in my backdoor. Digits in my mouth, dilators in the ears, chemicals up my butt, penises go in the hole I form by wrapping hands around.
Oh! I can math this thing. So a hole is a closed ring you can draw on a body that - if cut - would not leave the body in two pieces. In other words two orifices together form a hole. Then I'd say its the hole that is both my mouth and my anus. (Actually the anus also connects to nose, and sometimes ears, otherwise the ears are no holes at all).
So yeah, the anus-mouth-nose hole would be the one
Which of your holes are -potentially- open to receiving?
To the right implement, all of them are. When it comes to penises there is my hands-wrapped-around hole, or in very very special circumstances, the mouth.
Which is your favorite hole of others to insert?
I'd say the mouth, it is so articulate, warm and almost always you can see their expressions oh so more clearly. Plus it's the bitey part, and a little bit of danger just adds to the experience. Close second: The ears. Ever done a wet willy on a tied-up sub? Highly recommend.
In which hole did you last receive?
Receive anything? The butt. Ginger root still rocks. A penis? The mouth.
In which hole did you last insert?
Hands? Mouth. Toys? Pussy. Penis? Anus.
Had to think about the last one, it's been a long long time, and I am not looking to do that again anytime soon.
Have you ever received in more than one hole at once? Which?
So by this point I realized you were asking about specific orifices and specific implements lol.
Yeah so before I figured out why I hated it so much despite horny-me pushing me to try, I had received multiple penetration a number of times. Mouth and anus. (Or rather, the one hole that connects mouth and anus

)