Returning to the main question — as you yourself point out, even if torpedoes are not used, cheap and plentiful aerial and naval munitions will be employed. Aircraft and submarines will also mine the coastal waters.
Admiral Paparo has stated that the Chinese have air superiority over the first island chain. Now, air superiority is not an absolute, the USAF can and will deploy suppression of enemy air defenses, jamming, and other means to contest that air superiority and deliver penetrating blows, potentially with fairly impressive strike packages.
However, for the kind of economic commerce war that is being discussed, you may need air superiority to deliver a great weight of bombs. You need mass.
Even with modern smart munitions, you may be potentially looking at several hundred sorties to deploy several thousand mobile mines from B-21s. These minefields will have to be continuously replenished in the face of Chinese sweeping. One expects significant attrition to even the B-21 force with that kind of sortie rate into defended airspace - five percent is the historically accepted norm.
The elephant in the room is that at present, none of these weapons exist in quantity and will have to be developed or matured (as far as open sources are concerned).
New capabilities.
the primary objective of the United States will be to crush the Chinese landing on Taiwan and to deploy its own reinforcements on the island. Therefore, apart from blocking the routes between China and Taiwan, they will not be chasing every fishing boat in the region. There may even be the establishment of an operational zone, similar to what was done during the Falklands War
I do not believe the latter objective appearsly achievable for the USN. A US mechanized division requires several hundred thousand tons of shipping. The PLAN may lose sea control, the Chinese invasion force might falter, but it would be many months before Chinese forces could be sufficiently attritated in order to allow American infantry forces to be introduced into Formosa in strength. Of course, in the interim, they would probably stage through the Philippines and Japan, all the while under constant attack.
The United States probably does not have the strength in the Western Pacific to directly and immediately contest an attack on Taiwan. The Chinese possess over 1,000 reasonably good tactical aircraft and all the force multipliers of home base. As with the maritime strategy of the 1980s, which assumed some weeks to generate the multi-carrier CVBGs to enter Soviet Bastions, the United States will probably need to generate the forces to enter the region, which will take perhaps several weeks, as carrier battle groups move over from the Atlantic and aircraft stage through Hawaii. It would appear suicidal for the US Pacific Fleet to offer battle before being heavily reinforced, and expose the US Navy to defeat in detail. I would guess that it's a six flattop job at least, two groups.
The submarines will likely be targeting mainly invasion shipping, gathering intelligence, hunting SSBNs, attriting the Chinese Navy, and so on. They may well have their hands full.
We thought the same about Russia before 2022
Russia has not yet been defeated despite being economically outmatched approximately 30 to 1 and having the industry of a post Soviet state.
I find it strange to think that an economy 2/3 the size of the US that imports 80% of it's oil and 80% of that by sea through S.E.A., (not to mention the rest of it's global economic exposure) is going to sustain a high-intensity war of stealth fighters, hypersonics, space systems and the like with junks and coastal barges so small that they don't even register as merchant ships.
Chinese defense spending is only a small proportion of its gross domestic product. There is probably sufficient slack in the civilian industry to mobilize a lot of it for war and cannibalize a lot of it for war if necessary. This will not be painless to say the least, and while it is by no means a guarentee of victory as is sometimes trumpted--the world has marched on to means of war in addition to the industrial--it means a Pacific War could likely be conducted and waged for an extended period of time.
The real problems may well be the unknowns, particularly the ability of the United States to deliver unknown capabilities or extremely advanced multi-domain capabilities in the vein of the Israeli attack on Iran or the pager attack, as well as the fact that the United States military holds the ultimate trump card of nuclear escalation. Wunderwaffen have a checquered track record throughout history, but nuclear weapons might well do "better".
