all of those questions depend on the local standards of the opperating authority of a particular company or bit of rail line. none are any kind of universal standards.
helpers on the other end pointed the other way could be for any number of reasons. one might be some sort of pull-pull shuttle opperation, to avoid have to turn train or engine at one or both ends of its run. or if the helpers are cut off and sent back down the hill at some point this would avoid having to turn them at the point where they're cut off.
as for sequence of equipment in passenger consists, generally 'head end' equipment will be at the extreme end, or ends of train, food service cars, if present, in the passenger opperations in north america i'm familiar with, tend to be between coach/regular/2nd class end of train, and pulman/sleeping car/1st class end of train. from pictures i've seen of operations in europe, the seem to like to have the 1st/extra fare class equipment closer to the head end then the 2nd/regular class cars, unless the train is going in its return direction so the sequence is reversed in relation to direction of travel as a resault of avoiding the cost and complexity of turning the entire train.
i can't comment on the specific part of the world mentioned as i'm not familiar with it. and again all of this is really dependent on local opperating standards, proceedures and conditions.
the one thing i wouldn't do, is put baggage/mail and express cars in the middle of a passenger consist. but there may be exceptions to that too. to avoid extra switching/shunting moves, where the train is at some point split and each part then proceeds to a different destination.
