Why can not I pay with Bitcoin?
No we are able to buy subscription with bitcoins payments. They are using coinpayments to process bitcoin payments. You need to log in to find this feature as no where else it is mentioned.
If you want to have a lot of different IP with a lot of different locations for BTC faucet I recommend using a proxy
I believe proxies are less secured compared to VPN connections, this may be a reason people are looking for VPN services even in the need for just changing IP address. I suggest you to add more servers so that your services will be more attractive to this community as I do see many people here prefer VPN services with more number of servers.