This is incorrect, it would have been game over for U-boats that used their radios to broadcast once at sea.....this would lead to the development of new systems of operations while at sea,the non use of radios to broadcast while at sea. Something that should be covered in naval doctrines (although i don't think it will be as the doctrine was never used by anyone as far as know) Instead satellite's and short burst transmissions where adopted.
Throughout 1941, 42, 43 & 44, there were very specific "systems of operations while at sea"
http://www.ibiblio.org/hyperwar/ETO/Ultra/SRH-025/SRH025-8.html#s10 in order to counter RDF. Severely limiting the use of radio by submarines. They worked, but only to a certain extent. You see, in order to assemble a wolfpack, the spotting sub needs to tell its friends where the target is. So... the doctrines you mention were in-place.
A radio also comes in handy when trying to find your supply ship. Also not allowed!
Within seconds of switching its radio on (& I mean 2-3 seconds, so the 20 or so seconds required to transmit a regular encoded 23 (ish) letter report was far too long) it's bearing would be known, and, within minutes (if it can see a convoy, it's within ten miles) it would be under attack.
While the convoy is re-directed away from it's original course.
I have no idea what you mean by satellites. This is WWII. Sputnik was launched on 4th October 1957.
Short burst transmissions. If you mean Kurier, the Kurier technology was so advanced it took until late1944, and it was stil experimental then, for Germany to develop it sufficiently to counter radio direction-finding. Equipment that everybody had been using even during WW I so... fairly common but feindishly difficult to avoid.
Whereas Britain had been using RDF to track its own fighters during the Battle of Britain in 1940, so had loads of experience with its practical implementation and the only real delay in putting Huff-Duff on ships was perfection of cheap CRT oscilloscopes.
(Something that was a priority for RADAR anyway)
Why do you have to compete against the RN, or even invade UK? They produce very little resources on the mainland.
Convoys/escorts compete with the save slipyards as destroyers do and they cannot build all of them at once, they must choose. Every pound of metal, every manpower, every dollar put into convoys and escorts is a win for Germany and a loss for the allies because those resources could be spent elsewhere on aircraft, tanks, etc. UK working with limited resources because of convoy attacks is nothing better then a minor such as Hungary.
And that doesn't even take into account that anti submarine tech just doesn't exist in a useful form in 1939.
Now this I agree with. My point is, however, that anti-sub tech's
would have existed in usefull form, if Germany had started to upgrade their ship-building capacity in 35/36 in order to build masses of U-boats in 37/38.