Hey, sorry for the late reply.
- Yes, you can use the same recipient address on all miners
- Yes, you have to fund it to be able to execute transactions - to report your work,
- It depends on how many reports you plan to send; after 10 submitted reports the average fee is $2.61
- You won't be able to pay the transaction fee for the sending of the reports
- Of course, It's your address and you control it.
Thank you for your very good questions. I could make a FAQ out of them.
Good luck with mining!