Diverge e5 comp aluminium

Specialized Diverge e5 Comp/ Beginner Gravel Advice (2023)

I have been mostly road cycling and so a beginner for gravel looking at some gravel bikes for a bike packing holiday in Oman and looking for some advice for the dry gravel there! I’m limited with size being XS so not much choice with bikes

1) is there much difference in function with a 1by and 2by drivetrain. The Diverge e5 comp has 1by which the bike store people seem to think is sufficient and better easier to fix and change gears but I’m worried it won’t be enough gears on hills…

2) it doesn’t seem like it is tubeless compatible and the store recommended staying tubed. Has anyone not gone tubeless and had any recurrent issues with pinch flats etc? is it worth going tubeless to minimise the pinch flats or Would sealant in tubed tyres work similarly?

3) is carbon necessary? Price for diverge comp e5 2023 is $2500 whereas the carbon is $4300 AUD

Thank you!!