Arrange the bidding and play so that each player sees the other's bids and plays all at the same time so no one knows who is hesitating. This avoids UI and also eliminates a lot of the "faster please" comments. The software could also monitor each player's times and privately issue warnings to slow players.
I haven't looked at the other replies so this might be redundant but give 100% to W, this hand is an ace too good for that splinter. A reasonable auction is: 1♦ 1♥ 2♠ anything jump to 4♥ (a hand too good for a splinter)
a) North can't make a splinter and then decide to pass 4♥. Once S rebid 2♥ N should drive to slam unless they are off 2 quick cashers. He should start by setting trump with 3H which invites slam and initiates cue bidding. S should now cue 3♠ and N can ask for keycards.knowing the opps can't cash 2 spades off the top.
It depends on who you think is short in this suit. If rho then lead the J and play rho for Hx. If lho then lead small toward JTxx and play lho for Hx. Similar situations come up all the time.
Why would I ever want to take a call? Did I misread this? Hope we can hold it to -1. Oops, I just saw that I already answered this once. At least I am consistent.