US needs to win decisive battles before China fully focuses on the war. Demoralize the people on the mainland, but offer terms that don't make them feel cornered after US have accomplished fait accompli. That's the only way I see an invasion would succeed.
What I would do as US would be to first move nearly all naval/air assets into Asia, and then hit the SCS and towards Hainan with a massive naval blitz. With China focusing on keeping US away from the important south, US forces can more easily penetrate the 1st island chain, rapidly move airborne and marine troops into Taiwan and seize control.
From then on, it would be about keeping the supply routes open, which would only be possible if the initial decisive clashes were at least reasonably favorable. But if that can happen, America would be able to begin peace negotiations.
While China is unlikely to totally surrender Taiwan, US would have a strong negotiating hand if they have soldiers occupying Chinese cities. And if the fighting is contained to around the borders, there is a chance that most of the mainland population won't feel too threatened.
A solution US can realistically negotiate for would be forcing China to turn Taiwan into a separate associated region, like Hong Kong, but with US control and Chinese non interference written in a mutual agreement, to last x amount of decades, basically turning Taiwan into an US annexed area, while still placating accusations of overt annexation and playing to the sensibilities of America appeasers within China.
Warhawks in America would probably try to apply the "Crimea" model (Taiwan is now ours, it has always and will always be ours), but the thing is it would almost guaranteed lead to a forever war, because China is going nowhere, and they will just come back for Taiwan later after building up the military more, like Ukraine returned for the Donbass and Crimea. Not a long term solution.
That's not going to work.
Firstly, "assemble nearly all air and naval assets in Asia" - And the US should expect China to not notice (and be prepared to respond) at all?
Then, regarding the "hit Chinese man-made island bases in the SCS and towards Hainan in a massive naval blitz, drawing China's attention to the southern region and the SCS before move in to occupy Taiwan" - Hold it right there.
Firstly, in that case - Is the US military fighting the PLA of 2016, or is the US military fighting the PLA of 2023? Does the PLA only have one functional theater command across the entire country, i.e. the STC? Where did the ETC, CTC and NTC went?
Then, there's the mention of "strikes moving towards Hainan" - Hainan is not considered to be outlying islands of China like those man-made ones in the SCS or even the rebel island of Taiwan, but an integral part of mainland China itself. Attacking Hainan means attacking Chinese soil directly. I don't see how Beijing would see bombs and missiles falling on Hainan and just shrugs, saying "Meh, that's fine, let them. Haikou isn't as important as Guangzhou anyway"???
Then, there is Sanya, which is also home to the Shandong CSG and China's SSN and SSBN fleets. Simply put, Sanya is the Chinese equivalent of Pearl Habour/Kitsap.
So in case the US&LC attacks PLA bases in Hainan (or elsewhere in mainland China), China WILL retaliate in kind by striking US&LC military bases of similar importance in Taiwan, the Ryukyus, Japan, Guam, and elsewhere in the WestPac that directly participates in the conflict against China. And based on your stipulation, USMC bases in the region such as Futenma wouldn't even manage to move in force to Taiwan effectively and in time before the first PLA rocket artillery and missile barrages arrive.
Next, regarding the "US turning Taiwan into an American Hong Kong for XX years" - Lol no. The US main goal is to inflict as much damages to the PLA during Operation AR as possible, such that it would become utterly unfeasible for the PLA to proceed with Operation AR, and/or forcing Beijing to recognize that China has permanently lost Taiwan. An agreement like the "Hong Kong 99-year lease" isn't going to happen, because we are in the 21st century, not the 19th century.
Plus, until US boots are marching on the grounds of Tiananmen Square, Beijing would never agree to such demands. And China would rather press the nuclear button and even nuke their own soil than allowing US&LC troops to walk freely on Chinese soil.
Lastly, speaking of the "US occupy Chinese cities to appear strong during negotiations" - Like lol, lmao even. Where would the US&LC even base their invasion forces at, in order to invade mainland China directly, to begin with?
Vietnam? Guangxi and Yunnan are plenty mountainous and forested enough. If the US&LC wants to experience Vietnam War 2.0, feel free.
South Korea? North Korea exists for a reason. China is also an avid learner of history, they know what happens if foreign invaders weren't stopped at Yalu.
India? Good luck marching through the mountain ranges of Himalaya and the Tibetan Plateau. That region is several magnitudes larger and more extreme than Afghanistan.
Kazakhstan? Good luck crossing the Tian Shan mountain ranges and the Taklamakan + Gobi deserts. Those aren't your average Iraq.