The main problem with AC chair car is sitting for 16 hours. The human body is not designed to sit for such a long time. Your shoulders will ache, your head will ache, etc. Very difficult to sleep. Next day morning, you will be very tired and stiff.
Even non-AC sleeper is 1000 times better than AC chair car. At least, you will get good rest, and wake up fresh in the morning.

Tatkal is only a separate quota of tickets. It does not necessarily mean you will get confirmed tickets.

Mount Abu is 22 kms from Abu Road Railway Station.

thank you for the warning, abhishek. it will save me from wasting my money on this train. there are other cheaper options.

don't worry. go to the railway station at the time of departure. Your coach and seat will be on the chart at the platform.

I think your ticket is confirmed. But, sometimes they themselves don't know your seat number right now (maybe because of attachment of a new coach). At chart preparation time, they will know.

Please go to the computerised railway counter, and book your tickets.

The way it should happen is that Tatkal WL moves only if Tatkal ticket holders cancel. General WL moves when general ticket holders cancel.
Tatkal is only a special quota of tickets available at a higher price. Tatkal ticket holders should not get extra privilege of WL moving faster.
I don't know how exactly they actually move Tatkal WL.

It depends on what kind of ticket you have. For Tatkal, you won't get any refund now (24 hrs. minimum before departure).
For regular tickets, you will get about 50 percent refund, even 3 - 12 hours after train departure. If it is a really long distance train (greater than 500kms), then you will get a refund upto 12 hours after departure.

Very useful and detailed reply. Thank you very much.

Mr. Jain, how did you come to know that that passenger had 3AC ticket?

Thanks for the prompt reply, Mr. Jain.