TL:DR - my inspection contingency expires on Friday so I need to make a decision on this duplex in the next 2 days. I want it...and I THINK the repairs are reasonable...but I might be naive about what I'm getting myself into.

I'm in contract on an out-of-state duplex that was priced low, so I knew there would be a good amount of work required. But after getting the inspection report, I'm not sure if I should move forward with it. I planned to keep it as a long-term rental. But I'm worried the costs to make it liveable/safe might far exceed the value....even long term. There are a ton of little things that we (my roofer brother and I) can do in a week or two. Stuff like wall repair, new floors, outlets, cabinet replacements, etc. But a few BIG things that I have no idea how to price are:

1) there are some foundation issues but I don't know how serious. The floor is sloping and there are temp posts in the basement...holding up the rest of the house, it seems. For a contractor to put in permanent posts in a few key locations, what might that cost?

2) the inspector said the sewer was fully obstructed but some toilets do flush so I think it's partial obstruction...and could just be venting. One toilet doesn't flush at all but I've got a sewer cleaner coming out to take a look tomorrow. I do have a video of what the inspector found. But I have no idea what that might cost. Like, on the high end...a few thousand? Many thousand? Tens of thousands?

3) the gas was turned off on the house (even though one unit is occupied) so he couldn't test the water heater or regular heating system. Why would the gas be off? Just a payment thing? I didn't know the tenants were moving out when I got into contract but it seems they are so maybe they've just turned it off early? Any red flags I should be aware of that could cause more costs when I have the gas turned back on?

If anyone is willing to take a look at the inspection report and help me ball park the "major" issues, I'd appreciate it. Obviously, this is my first rehab and I've only ever remodeled houses to live in them...not to clean it up for renters with a tightish budget in mind.

the pix in the basement. (and yes, there is obviously water damage to deal with. There are some holes in the outer wall that we'll fix and will hopefully stop future water intrusion...but I don't know the climate well enough to know what is "normal moisture" in this region...

Do these seem like "medium" priorities? They seem kinda urgent to me...