running Time Capsule over I-Phone6 hotspot

I would like to terminate my uselessly slow satellite wifi and instead use my IPhone6 as a hotspot for Wifi plus automatic TimeCapsule back-up's.

a) Is that possible?

Sorry, but no. Reason....the Time Capsule must connect to a modem or network router using a wired Ethernet cable connection. It cannot wirelessly "join" an existing wireless network.

There is one exception to this......IF......you already have another Apple AirPort router set up to provide your wireless network......THEN.....the Time Capsule can be configured to connect to the wireless network and extend the wireless network.

Rather than use the iphone as hotspot.. buy a proper 4G wireless router with ethernet.. and a separate sim card for cheap data only account. In the end this is going to work better anyway. Most of the big ISP and Phone companies sell this kind of gear for very reasonable prices. Just make sure it is not purely a hotspot but has an actual ethernet port.. which will make it more expensive or an added attachment.. but long term well worth it.