The reserve price is there just to act as an abort mechanism. Say if you wanted to make a minimum profit on a player, you would set a reserve price so that if the players price fell below the value you needed to make your minimum profit then your shares get removed from the queue and you abort the sale. (without you actually having to be there to do anything) This also works to minimize a loss, say if you were ok with making a 5p loss on a player but no more then that, you would set your reserve price to what ever the applicable value would be and if the price falls so that you are losing more then 5p per share again the shares are taken out the queue.
What you describing with seeing lists of players etc will come but to do that you need FI to introduce order books, do a massive tech upgrade and get a spot of help from NASDAQ to make it all run smoothly. This is the direction that FI are going in, but it will take some time to implement.
But basically at the moment there are only 2 prices you can sell at the current price (whatever that is, at the time when you are at the front of the queue and the next person buys your player) or the Instant sell Price which will make you a loss in most cases and at best will stunt your profit on the player, therefore should only be a LAST RESORT.
You are correct in that yeah you are at a disadvantage as someone could sell their shares at a higher price then yours, but that's just how queues work. No different to waiting in line to but a ticket only to be told when you get to the front that all tickets have been sold, it sucks but its just one of those things. Hence why FI want to move in a different direction with order books etc. But the reason this happens is mainly because while your queuing up waiting to get the best price you can, some other guy is Instant selling causing the players rice to crash, hence why the earlier you can get in the queue the better.