Let's say the short term goal of the violence was to draw in PLA/PAP (I've heard this too). Even if PAP or PLA was to come in and just start shooting everyone, what would the end game of even this be?
The funny thing is I don't think the rioters care. Before, these rioters are nobody. Now, they think they are somebody. That's why they are so obsessed with the media and foreigners especially the foreign media and foreign governments. They want the world to look at them as some sort of martyrs that fight for freedom and injustice. Sadly, they don't understand most westerners are just shedding crocodile tears.
1. Invite Western military intervention to "save" HK
This is the most outrageous of the possibilities I have heard. Basically you want to turn up the violence to a level where it prompts some kind of massacre to happen in your own city. As if this level of mass death was not enough, you want a war to happen and more people to die? Heck, it would likely be some kind of World War were it to happen. Furthermore, this would be so blatantly ignorant of reality, the US didn't liberate PRC after Tienanmen, they didn't liberate Crimea from Russia either.
2. Sanctions to collapse the CCP and "free" China (or at least HK)
Sanctions don't work. History shows it. Fidel had a nice long career and life. Sadaam was ultimately brought down by another war, not sanctions. Putin is still around. I posted an article in the Economics thread, Huawei was already able to turnaround an "America-Free" phone. Jimmy Lie, spreading unrealistic ideas to promote his/America's agenda.
Most of the rioters are hoping that the second scenario would occur. Like other members said for the brainwashed radicals "If I don't get my way, no one will get his/her as well." But for some one like Jimmy Lai, he has a more realistic expectation. Jimmy Lai knew that President Xi is under tremendous pressure due to the Xinjiang, trade wars, and now Hong Kong. He thought that if he could force the central government to send in the military, then a worldwide(western) sanctions would cripple the Chinese economy. Jimmy Lai is hoping that other factions with CCP would force Xi to step down and a more moderate leader within CCP would assume control. As long as it isn't Xi, Jimmy Lai and many elites in HK think that they could coordinate with the fellow liberals in China to bring down the CCP like they were doing in the last few decades. They think they come close of weakening the CCP before Xi assumed the role of president.
I think this is the obvious sign of how the so-called "leaderless" is simply poison for HK, tailor-made just to sow discord, and chaos. None of these outcomes are realistic, or actually benefit HK. The reason the "black hand(s) behind the protest" theory is so popular is because the actual motivations are so murky, and any real realistic positive outcome even more so.
Sadly, it is never about HK. It is more a desperate move by the western powers to make a last stand before China became unstoppable.