As far as an urban survival knife goes just like a wilderness survival knife I'd much rather have a small fixed that any folder. The size would depend on the situation. So far the RAT HEST is exactly what I wanted for the current situation. In a SHTF situation where laws no longer applied it would be back up for a larger knife or would be backed up by a larger one in a pack. It's easily tucked away, stoutly made, fits my hand well, handles great, and is easy to keep a grip on. Granted I could likely do without the bottle opener but I don't mind it being there at all and will think of things to use it for I'm sure...even if just opening bottles or lifting wire handled pots off a fire. It is always good to have a folder on you, better for any tasks it will handle when done around people without drawing any unnecessary attention, but when it comes down to it I want a fixed blade when I need one. I've even had some very small ones made just because of that
I've been lucky in that in my line of work I always have a Breaking and exiting kit with me in my truck and with me at work anyway...I'm a carpenter. I have lots of tools but I have yet to see the building I couldn't get out of with a good straight clawed hammer and a heavy pair of Kleins with insulated handles. Multi-tools are great, I have a few of them, but cutting flex conduit or romex with them would be a pain in the neck to say the least, and very dangerous. tearing sheet metal with them would likely ruin them. I ruined my first leatherman cutting tie wire.
And whoever said punch a hole in the dry wall and then start pulling and then push the other side out was spot on. That's how we do it when we do tear outs. When chopping your just going to make a trench but by pulling and you can remove much larger pieces. Heavy boots, any chair with legs, even a bare fist in a hammer blow will do to start the hole. If there is someone there you don't like you can use them to start the hole

...just use your imagination drywall isn't that durable.