If you agree with first premise then it is easily to see how capitalism is exploitation by force. In fact every economic system require force, whether capitalism, socialism, or etc. At the most basic level, you need force over nature.
Let talk about an example. In your company, if many workers only want to work 8 hours a day, but you want them to work 12 hours a day. Do you accept their demand? Of course not, you will force them into submission by firing all workers who refuse to work 12 hours a day.
Or for example, the workers voice their opinions that you should allow them more times in order to polish the end products, but you don't want to do that because it will cut into the profit. What to do? Of course forcing them to work faster by cutting corners either by profit bonus or other ways. Anyway, it is force, because you can control other people to do what they don't want to do, by which means, it's not important.
You should discard the notion that force is something inherently bad. No, there is nothing bad with force, but only wasteful or harmful way of using force.
2. and 3. You should read my points carefully again. I don't talk about whether capitalists deserve their riches or not. We are not Gods who have right to judge other people. I just want to talk that it is nearly impossible for normal people nowadays to live their independent lives from the capitalists, because either they don't possess capital, or cannot risk borrowing from the bank, as the average rate of profit of our days is near zero already, if not negative. There is very high chance to lose everything rather than succeed.
Anyway, are you really a capitalist? If you are a true porkie, I think you should quickly understand what I said.
4. In the main ideas, you're right, the system will return to capitalism. But you should focus more on the lower nature of economic system. You only see business as the smallest division of the system, and economy is nothing but rearrangement of those businesses (atom). However, it's necessary to see that in reality, a single business is not a self isolated thing, but a mobilisation of many labour force from everywhere in the world. Without seeing that fact, the picture is very mystified.
5. In socialist society, the profit indicator should be abolished. The economy should be control by a public plan, which everyone could check and voice their opinions. In fact this is what happened in Soviet Union during Five Years Plan. The GOSPLAN only decide the input and output of each company, but don't care about its profit. The mission of every company is to fulfil its plan, nothing more, nothing less.
The downside of this system is that it's very hard to optimise the quantity of output products, as there is no powerful tools to force the workers to work hard. The profit indicator of capitalist is actually more powerful the force of the state. Therefore, by switching to this economic model, we must sacrifice the ideal of maximising total GDP growth.
So how could a system like Soviet Union possible? It's only possible when GDP don't correlate to actual power in reality anymore, in other words, when a high GDP country, such as the USA, cannot defeat a small country with much lower GDP, such as Iran or North Korea. The condition during early 20th century was exactly as such. As the capitalist nations were busy fighting each other, the USSR could develop in a rather stress-less environment. But in the latter half of 20th century, when all capitalist countries united to fight against USSR, the planned economy wasn't viable anymore, so they switched into a hybrid between socialism and state capitalism (Kosygin reform), where the state controlled the economy by profit indicators.
However during 80s, when the crisis hit, the profit of USSR was too low compare to the rest of the world (due to their socialist policies), so there were only two ways out for USSR. Either return to planned economy (as the environment then was quite peaceful, and they just won the war in Vietnam), or restructuring by discard the low profitable parts of the economy. Sadly, they chosen the second choice due to inactivity of workers and state managers (they're too lazy to do planned economy, control the economy by profit indicators were much easier) and other capitalist roaders elements in USSR. The rest of story is history.