Almost forgot the sleeping Kraken,
"Also, there is an irritating bug or delay that wont let me onto the deck gun after I have surfaced. Meanwhile the enemy are scoring hits. Any ideas on these 2 issues ?"
No idea how to hack that, problem is the subs have a set depth that the gun crews won't go on deck, so you can't either. For US subs it's 21 feet, on surfacing even with emergency blow they hang at 22 feet for a minute or so before rising to 21. Reflects real life, they blew the tanks with high pressure air, but that left some water in the tanks. US subs finished emptying the tanks using low pressure blowers, took 15 minutes or so to come up to full surface trim. German U-boats directed the diesel exhaust into the ballast tanks instead of using low pressure blowers, in theory the oily exhaust coated the inside of the ballast tanks to reduce rusting. Either way there will be delay.
Another option;
www.subsim.com/radioroom/showthread.php?t=211613
My subs are hacked for that, with 40mm BOFORS (even single!) fore and aft I can start blasting destroyers when I rise to 30 feet or so, if decks awash is set for 26 to 27 feet it's harder for the bad guys to see or target the conning tower while you're punching holes with a 40mm. You could also surface all the way, but as soon as the AA gun button lights up go to one of those and fire at the closest destroyer while you're waiting to get above 22 feet.