1) 2.7 petrol is good for on road performance and cruising purposes on light usage, if you plan to utilize full capabilities of the vehicle, get the 1kzte, robust as hell and performs like a charm.
2) On both you can expect around 6-7 local, 8 ish long, if driven carefully and ideally, theses values can vary.
3) They are both easily maintainable based on your mechanic, if you have one who understands SUVs and deal with diesel and petrol engines. The major difference is that the diesel is robust and can bare bashing
4) They are available, don't know about your definition of easy, each SUV has their particular parts dealers, so nothing is unavailable
5) It all comes down to condition, usage and requirements. TLC 80 is a lovely machine, is more economical as well. But again, this discussion can only be proceeded based on your wants and requirements from the vehicle. Surf is usually not preferred only because of its unorthodox driving position(so do take a test drive before finalizing on finding a vehicle). FYI TLC 80 is also a 5 seater
6) It all depends on the condition, initially about 100-150k maintenance is a must upon purchase, and after that, both would work similarly. But like i said, 1kzte is a bit robust, so there is that advantage.
As for your later concerns, Pajeros are not delicate, with the right mechanic and timely maintenance, they work like a charm, much like all suvs.
If you would be kind enough to mention your utility purpose of the vehicle, it would be easy for people to properly guide you.
Have a nice day
