No, not really. The government has been stacked with pro-Beijing people, who have all the executive and legislative power. The only choice people have is to vote for new representative, from a slate of options picked out by the CCP.
That was the reason for the 3-month long '14 protests. You can see their effect today.
There are no paramilitary/security forces loyal to Hong Kong capable of a coup, right? Just trying to put it in context with contentious protests in other nations.
The short answer is no. The People's Liberation Army has a Hong Kong garrison with ~6000 troops that could crush pretty much any coup attempt. The only security force that could even in theory do what you are asking about would be the HK police force which has ~30000 officers.
This doesn't even get into the bigger logistical issues around HK severing ties to mainland china. Last I checked HK is depended on water from the mainland which makes being fully independent of mainland china basically impossible.
More than enough to deal with any other form of armed opposition in the city. There is a question of just how far the PLA would be willing to go if things got out of hand, but that really isn't something anyone wants to test.
I disagree. A government usually requires less than 4% of the population forming an armed resistance to remove them, the protests have turned out about 14%. Assuming your typical home made bomb kills about 4 soldiers it would take 1500 bombs and that's not even including casualties from other things, a single person could probably accrue that across the span of about a year if they built 4 a day. 12 people could do it in a month, plus say 40 people for carrying out the operations and acquisition of materials, give or take so lets say 60 people per unit of the resistance, that's like 280000 resistance operations going simultaneously.
Obviously I'm making alot of assumptions here, but I think they're reasonable. The real tricky bit is what you do after you remove the government as demonstrated by Libya and Syria.
That was the reason for the 3-month long '14 protests. You can see their effect today.