How tons of cargo will be measures is by adding weights to the ship and seeing if when they sink

Hover Craft:
Ability to carry at-least 5 net tons of cargo, maximum of 20 net tons
Maximum of 2 auto cannons with maximum of single barrel
Maximum speed of 80 knots
Can be operated on land

Landing Craft:
Ability to at-least to 10 net tons of cargo, maximum of 50 net tons
Maximum of 1 auto cannon with maximum of single barrel
Maximum speed of 40 knots

Landing Craft carrier:
Ability to carry at-least 4 landing crafts, maximum of 16, can also carry hover crafts
Maximum of 16 auto cannons with maximum of duel barrel
Maximum of 30 machine guns with maximum of single barrel
Maximum speed of 32 knots

landing Craft carriers should be used when landing Craft does not have enough fuel or if the sea is too rough

Ocean Liners: 15UC
Ability to carry at-least 850 net tons of cargo, maximum of 4000 net tons
Maximum of 10 machine guns with maximum of single barrel
Maximum speed of 55 knots

Yes, ocean liners was used, they were used as they are just too fast for navy ships to catch, it’s not a war crime to sink one

Cargo Ships: 25UC
Ability to carry at-least 2000 net tons of cargo, maximum of 7500 net tons
Maximum of 4 auto cannons with maximum of quad barrel
Maximum of 8 machine guns with maximum of single barrel
Maximum speed of 35 knots

Q-Ships: 30UC
Doesn’t need to any carry cargo, but they can carry up to 5000 net tons of cargo
Maximum of 6 single barreled 5 inch guns
Maximum of 2 single barreled 2 inch guns
Maximum of 4 auto cannons with maximum of quad barrel
Maximum of 8 machine guns with maximum of single barrel
Maximum speed of 35 knots

Cargo fleet gun reloads are same as Blue Seas Fleet gun reloads

Q-ships, also known as Q-boats, decoy vessels, special service ships, or mystery ships, were heavily armed merchant ships with concealed weaponry, designed to lure submarines into making surface attacks. This gave Q-ships the chance to open fire and sink them. The use of Q-ships contributed to the abandonment of cruiser rules restricting attacks on unarmed merchant ships and to the shift to unrestricted submarine warfare in the 20th century.

Q-ships can also be used to sneak into enemy formations flying the enemy’s flag, at night it can lower that flag, raise their own flag, reveal their concealed weapons, and then open fire on the enemies before hiding all of their hidden weapons. Using this strategy won’t always succeed however, it will also lower your reputation if word of it gets out

Hospital ships: 20UC
It’s a hospital ship, just convert a cargo ship or an ocean liner, you can heal troops there, this ship will be mainly used as a forward operating base, but keep in mind the resources on the ship will run out, a hospital ship will be able to heal twice the amount of troops to the net tons it can carry