there a way to
 

delay leaving the bridge when diving? it's just too quick

Although the time it takes to clear the bridge is a wee bit too fast, the time it takes the boat to submerge is realistic since the crew belowdecks already started with the submerging process while the watch crew was getting inside and securing the hatches. So it's a good idea. Maybe it would be possible to leave the crew on deck a few seconds longer. Animating them surely will remain a dream.

Along the same lines, I wish that the default location when diving was the conning tower instead of the control room, as that's the first place you end up.

I always right-click myself into the tower before I hit any dive key, just so I end up there.

Same here, plus I like to see the boat diving through periscope. Reminds me of those old WW2 movies made via the scope or a bow camera during dive/surfacing.

would it be possible to edit the string to end up say where you want to?

in SH4 the bridge watch does go below but i remain behind for several seconds and actually end up underwater before i go below:-? . i take it there's no file that can be edited, huh