Can I save money by switching to mobile broadband?

Here's the deal: I live in Orange City, Central Florida, USA. My parents currently pay $161 a month to Bright House for Cable Services, Internet Phone and Cable Internet.

They also pay $171 a month to T-Mobile. We have 5 phones on our plan, one of which is an iPhone 3G which uses a 200MB per month Edge data plan. The rest are standard cell phones with no data plan. All the phones have unlimited texting and I believe we have 700 minutes shared between the 5 of us?

Is there a way that we can ditch the Internet Phone and Cable Internet with Bright House (only retaining Cable TV) and open up a phone plan in which we get a fast data plan to have as our home's internet connection (connecting to the internet via Mobile Hotspots), SAVING MONEY in the process?

Basically, my dad wants to ditch the cell phones altogether so none of us have phones. He doesn't want to spend the money anymore.

But here are my concerns:

1. Land lines are becoming obsolete, and I personally see no point to paying for a land line when we have cell phones. Am I missing something?

2. Is there any point to paying for all those channels that Bright House offers when we only watch a small fraction of them?

3. Is it really a wise decision to get rid of one's cell phone plan in this day and age, but KEEP the land line?

4. If we have a lot of devices in our home in which we use Wi-Fi (e.g., game systems, computers, etc) will all of those devices be able to run on Mobile Hotspots at once? My brother plays a lot of video games and people in our home are almost always using a computer. If people are awake, it is rare that one is not being used. What are the levels of speed that are offered? Obviously we would be getting an unlimited data plan in this scenario.

Basically, to wrap this up, is there any way I can convince my dad to go along with this? The whole family is pretty ticked about this whole thing -- he's been cutting costs on a lot of things that we ENJOY and utilize FREQUENTLY, but not on things that would actually be a wise decision to cut costs on (e.g., constant wasteful unnecessary spending on garbage none of us want). He says he would be open to the hotspot plan, but the big question is... Can he save money? If he can't save money, then the rest of us are all screwed as far as having phones goes. The whole theme behind this past year in our home has been "cutting back". Everything's about saving a buck. Quality be damned, unfortunately. I want to provide to him a cheaper alternative to what he has now, because the only thing that would make an idea attractive to him would be saving money. It's not like he disapproves of us HAVING phones, but he simply does not want to spend the money on it anymore. We would really like to continue having cell phone service but since my dad makes the money so he makes the decisions. Our contract is up at the end of this month, and he has confirmed that he will NOT be renewing the contract. He HAS been looking at other plans from other providers (we are dissatisfied with T-Mobile's signal strength and always have been) but he's finding that they are even more expensive. It's funny, because his whole reasoning behind picking T-Mobile for our provider was because they were the CHEAPEST around. (Seems like you get what you pay for, hmm?)

I am hoping that the idea of turning our devices into hotspots for the whole house to utilize would be a feasible idea, but I am not sure if it actually is. He needs to save money. I really need some help. Anyone who would be willing to provide interactive help please email kevinmahoney1995@hotmail.com. Thank you.

PS: Should we be looking in the realm of prepaid phones and not contracts? He's been looking at both and is still dissatisfied with pricing. It's just not low enough.

And about TV antennas -- although my father has thought about switching TV providers as well by just getting an HD antenna which is a completely different topic, but if you have any suggestions on what to do regarding an antenna please post it here because frankly I do not watch TV at all and if he wants to switch to something cheaper on TV so we could still have phones i would be VERY receptive to this because I could not care less about television AT ALL.