It’s a little hard to make out exactly what you’re asking, but I will try to respond to your questions.
Left click on the trash can then left click on the order you want to delete. It’s not a drag and drop system.
I tried in north Africa and didn't work. I will try it again with USA. I didn't use drag and drop. Anyway drag and drop is so easy to use and make mistake (Paradox is genius for that)
Guadalcanal is in the Solomon Islands and is controlled by Australia at game start. It is East of New Guinea if you are looking for it. Of course, you’ll only have to recapture it if the Japanese actually take it, which is far from a given.
Found Guadalcanal. It was the main base for USA with Australia. The distance plane can afford at this era is very limted. It's why USA planned a step by step from iland to iland. No choice at the moment of WW2
It’s possible to plan a follow-up order after a naval invasion, not sure if this can be another naval invasion or not, though should be easy enough to set up once the island is retaken. You won’t be able to build buildings at Guadalcanal since it will be liberated to Australia, not you. You will still be able to launch naval invasions from it though.
With better control of army and the task force we should do it. After all you control a sez area when you can choose who go in this area. Even like a land province. But you need suitable naval base...
North Atlantic campaign is simulated through Germany using U-Boats (submarines) and the UK trying to counter them with destroyers/cruisers/aircraft. The Germans use convoy raiding mission and the Allies Convoy Escort/patrol/strike force. Any German convoys coming from out of Europe should be easyfor the Royal Navy, or even Royal Canadian Navy to blow out of the water with surface ships or submarines, as they will likely be unprotected.
AI in HOI4 (and previous at all) don't know that. I think it can be improved. If we can assign a task to a fleet and very clear like : Chose one of the following task, protect , control, attack, defend and after the specification of the area. AI should handle the rest and claim for renforcement (This pattern can be use for ground) That will permit to a fleet to help another if her sector is quiet and vive versa.
The USA does have more ships and dockyards than Japan in game and will try to (and very much can in player hands) strangle Japanese trade and convoys with submarine warfare.
The way to give this order is not clear.
The Italian Navy couldn’t really challenge the Royal Navy, even with it spread out, in actual WWII either. It could get a few convoys through with proper air support and threaten sneaking past British assets for naval invasions, but not really a 1v1 fight by any means.
In OOB i had to invade Malta to permit the passage of italian convoy. It's virtually impossible In HOI it"'s so easy and simple...Should be one chance on ten for success but is not the case.
Sent to, but were they actually at the same base? Also, for ease, you can right click with the ships selected to assign them to another navy/task force, and they should travel to it/it’s mission.
For Canadian Fleet they was at the same base but no merging worked
On naval production que instead of auto-assign, which will add ships to reserve, you can left click and it will give you the option where to assign new ships, including directly to fleets.