nr 1 bus, runs every 15 to 20 min

no

No tour required . There’s a good map and I just walked in and bought a ticket. Spent about 2 hours there and lots of little tracks to explore if you’re fit ( some very steep)

I don't think so. You wouldn't get the full experience and there's a lot to see and take in. I'd recommend at least a couple of hours.

You can take the elevator up. But there are lots of steps to get into and out of the caves and they can be steep with no handrails. There are also steps from section to section outdoors. Again, they can be steep but there aren't steps - maybe 6 max. at one section. If it's wet, I wouldn't recommend as it would be slippery. But if she has an arm to hold, she may be ok. And if you're both ok with it, she can wait for you outside some of the caves while you go in. My main concern would be other people - I would imagine that when busy, there will be many others there and as we all know, people can be pushy, self absorbed and so attached to their phones and selfies that they pose a risk to the safety of others.

Hi All you pay for is to use the lift. There are stairs which I used so no cost. Enjoy

No, sorry

Hey i think i saw the shop but the price will be definitely higher..i brought one marble bracelet for around 2 euro

Yes, 40.000 Dong entrance and 15.000 Dong for the elevator.