Lego Train Questions

[Gad-Westy]

Kids are old enough now that I recently got all my childhood lego out of storage for them (erm and me) to play with. They're loving it but was slightly disappointing to find my old 4.5v steam train is dead. To be honest it's a shame but was of limited fun even as a kid.

I'm pondering buying some new train stuff but I see it's all changed.

So some questions:

Can then new style track be connected to the older track at all?

Are the new flexible track members worth bothering with if I just want to lay out simple tracks? I assume not?

Do the train couplings work the same? Flexibly mounted magnet inbetween two buffers? would be nice to use the old trucks etc.