Hello all!

We have just moved into a house with a new 16x34 ft in-ground pool with a vinyl liner.
We live in Canada so there was significant amounts of snow and ice, so we could not fully examine the pool before buying the house. We knew that the vinyl liner was quite old, and needed to be replaced, yet we have some new unanticipated findings and are hoping to get advice.

Obviously, hindsight is 20:20, and I should have known better and should have put significantly more conditions on the house needing a properly functioning pool in the spring, yet I'm just trying to focus on the future and trying to get as much advice as possible.

THE PROBLEM - Vinyl liner, massive leak, wall heave:
The vinyl pool liner is also very brittle and has cracked and is floating in some areas. So certainly the liner needs to be replaced asap.

It sounds like there is a large patch on the deep end where an old main drain was patched over and probably not properly sealed. When I started vacuuming all the leaves, there is now a very substantial leak! The water level is decreasing by approximately 1 ft per day! Our sub-pump in our house has been going off every few hours because the water is draining into the collection reservoir.

The concrete pad is not connected to the pool or the coping and so the two are independent which apparently is more common in older pools? Two walls are starting to heave and is approximately 2" displaced forward from the concrete pad of the pool. Therefore, it's impossible to know when the wall has started to heave from the concrete pad above and if this is an ongoing issue as it could have occurred very recently or potentially has been stable for many, many years like this.

WHAT SHOULD I CONSIDER?
I guess now that we have noticed these issues it's easy for my mind to wander and think what else could be wrong with the pool.
There are some larger trees in our neighbor's yards and so with the numerous patches that have occurred over the years, I do wonder if potentially trees could be causing issues themselves.
Probably it is just the prior owners just patching things and not dealing with the issues as they came up.

SOLUTIONS?
We have three local pool companies coming out in the next two days and one company that is already come out and recommended that we replace the vinyl liner, which makes sense.
They also said because the concrete of the deck is not attached to the coping or the steel wall that the deck should be demolished and poured again and connected to bullnose coping. He said he would do this to add structure and support to the walls so they don't heave in more. Sound reasonable?
They also said they would put in braces and frames in the areas where it is heaved forward. I believe they were called x-frames but I can't recall the specifics. He did not give a price point on this as it depends what it looks like and how involved it will be.
Right now I have a quote as follows (in Canada): vinyl liner $7,500, remove and pour concrete $8,500, bullnosed coping $2,000, and then replacing the skimmer basket, and some odds and ends and the the total is $22k + whatever bracing is needed. The timeline would be 3 months away before they can do it.

QUESTIONS:
How dangerous and bad is it that the pool is going to be draining near the basement, and the sub pump is going off?
Once the water has completed draining out of the pool, depending on where the water table level is, would it be bad to rip out the very old and brittle vinyl liner and see what is behind it?
I'm very interested to see the bottom of the pool and so if the water table and water level does not allow me to fully access and visualize the bottom of the pool canI pump it off visualize it and then refill water back to the water table level or would that be dangerous for the structure of the pool?
There was also talk of demolishing the concrete deck, and then I could dig down by the seams where it is starting to heave to try to relieve some of the pressure until the work can actually be done.
Right now we have 2x6s bracing the pool, which can be seen in the photos. Does this look adequate or should I add more? Or do you think this is overkill?
How ridiculous would it be to just replace the vinyl liner and then follow along and see if the wall starts to move or heave at all in the future? (and thus not touch the concrete pad that is independent)
Would the bulnose coping provide enough structural support to prevent heaving in the future?
Should I be worried about the bulnose coping failing sometime in the future and then needing to replace the patio concrete again?
Also, how much is time of the essence in terms of fixing this? The prior quote is for September. We won't be moving into the house because of other renovations, so we wouldn't miss out on a pool season as we have our current house has pool, but I don't love the idea of having a completely empty pool sitting there for numerous months. Someone said they probably have availability in the next month or so. How much of a price premium should we be paying for this?
How much of this work do you think we could do by themselves (as if it's just elbow grease a jackhammer, wheelbarrows, Etc I would be comfortable if we are bringing down the cost)?
Anything else that I should be asking the future pool people in terms of input and pricing and ideas?

Okay, that is probably way too many questions, but as you can tell, my mind has been racing, and I certainly would love any ideas for input or advice or what to be asking the other pool places.

Certainly, I can provide more information and clarification if needed.
I will take you along on this ride as I go through it.
Certainly a stressful and memorable ride, and hopefully not too ridiculously expensive.

My Pentair SuperFlo 1 HP pool pump has been slightly leaking and it is making sound while running and also getting hot. So, I am looking to replace it with a Jandy FloPro 2.7 HP motor. I bought the motor almost new and housing used from someone. However, the backplate within the housing has a screw stuck in it, so I may not be able to use it, but if I need to use it, I need to buy new diffuser and backplate. So I am investigating if I can use my current pentair's housing with this pump. I have the below questions:

1. Will the current Pentair housing fit the Jandy motor I bought?
2. Will my aqualink system will work with the Jandy motor and will I be able to control the variable speed of the new Jandy VSP motor if it is connected to my existing aqualink system? Currently I use an app to switch on and off the current motor and the app connects to the aqualink 2.0 device attached to the aqualink RS system via Wifi.
3. The current pipe diameter I have is 2 inch. Is my new 2.7 HP pump too powerful for my current pipes?
4. The current pool filter I have is a Hayward C1200. Will the new 2.7 HP pump be too powerful for my current filter?

Here are the details of the equipment I have:
Old pump:
Model name: Pentair SuperFlo 1 HP (Model SF-N1-1A/340038)
Motor model number: 196238
Housing model number: 350089 or 354704 REV D (not sure)

Current Pipe Diameter: 2 Inch

Current Pool Filter: Hayward 1200

Current Power center: Aqualink RS Power Center (Model 6612F or 6613/6613AP)
iAqualink 2.0, Aqualink: REV T.2, FW Rev: 4.0.6-w

Current Time Switch with Transformer: Intermatic Model T10004RT1

New Pump:
Model name: Jandy FloPro 2.7 HP (Possibly model#VSSHP270DV2A)
Motor model number: B0245806
Housing model number: VSSHP270DV2A (The backplate and diffuser are damaged and might need to be replaced if I need to use this)

Any help is really appreciated.