Yep. Except, you missed two steps:
Step -1: organization of Vanguard
Step 0: Vanguard Party organizes Proletariat to actually let it seize the MoP (it's industrial society we are living in; you can't just "seize" anything by murdering some people).
Nope. At this point Party becomes/creates government. Even if real people will keep significant influence on things, there is a crucial difference.
No. That's a strong "No". Neither Socialism nor Communism is gift economy.
If we are talking ML, Revolution is not limited to "seizing means of production". This is when transition period begins. Well, IRL we will get "reconstruction period" even before that (dealing with consequences of Revolution/wars).
For ML this step is Socialism: rapid industrialization of the state, until we are all sufficiently wealthy. At the very least, that means that we increase productivity of our work, until we earn 4-5 times more than we do now, but work 4 hours a day.
Revisionists (see Bolivarians, as an example; or late USSR) don't do it, try to avoid it, or don't put enough effort into it. Which is why they fuck up and crumble into Capitalism. Socialism works only as long as society is advancing towards Communism. Not unlike bicycle. Industrialization (and - yes; mostly planned economy) is this next step that cannot be avoided.
Also, see Piketty's to get the general idea. Keep in mind, that he is pandering to the Capitalists and tries to present Socialism as compatible with Capitalism (SocDem, basically).
Socialism is a process of displacing Capitalist elements (unregulated scarcity) of economy with Socialist (democratically regulated scarcity) and then Communist (mostly unregulated due to abundance).
Not necessarily true for all countries.
Capitalists will get scared of revolutions and some start allowing partial reforms. See picrelated: US and Cold War. No actual revolution happened, but Capitalists got weakened anyway. Some countries might experience gradual transition to Socialism (at least initially), instead of full-on Revolution.
As I've pointed out, Vanguard effectively stops existing before Step 2 (even if it keeps the name, it is not VP anymore, it has different functions).
Government becomes truly democratic, dissolving it's functions among the population. It's not immediate process.
Yep. Being pragmatic I don't really care about this part, though.
What is Communism? This "Step 6"? Or Socialism (Step 3)?
Personally, I think currency/market will be slowly shifted out of use, maybe staying somewhere as an oddity. Horses did not disappear completely, despite cars making them mostly obsolete.
You missed the whole point here. Communism is post-scarcity economy (Step 6). If you have scarcity, it is not Communism.
Scarcity economies are either Planned (democratic decision on what to do) or Market (whoever has more money decides).
NB: you can have post-scarcity in one area (healthy food for everyone), but scarcity (luxury food) in other.
No idea. Depends on circumstances.
In general, things are divided into luxuries and necessities. Scarce luxuries can stay with Market (i.e. if you have some surgeon that is very good at making elf ears, you throw money at him until he agrees to turn you into Special Snowflake). On the other hand necessities mean that society intervenes and establishes some procedure (i.e. if there is a dying man, surgeon needs to treat him first, rather than make you special snowflake elf ears).
Questions?