Is my exhaust causing misfire or did misfire burn the exhaust?

I hope to not be too vague as I don’t know a lot about cars.

I recently purchased a 1.2L Fiat Punto II 2005. It has trouble with a rough idle, a power drop off around 4krpm when accelerating and a general sluggish feeling to the acceleration. There is a hole in the Flexi part of exhaust also. After driving for a couple days I can tell fuel consumption is much higher than it should be

Returning codes:
P0300 – random/multiple cylinder misfire
P0170 – Fuel Trim Bank 1
P0130 – O2 Sensor Circuit bank 1 sensor 1

Now from the researching I’ve done it seems the hole is likely caused by burning fuel after misfire on the exhaust, so I don’t want to replace the exhaust for the new one to burn through too.

On the other hand It seems that the hole may be tricking the car to think it needs more fuel to the point it is too rich and can’t fire under load?

Any input from more experienced persons would be much appreciated!

Thanks