Yes, yes, yes!
The real question is what CAN the central banksters actually do?
Get governments to pass legislation and start overtly or covertly threatening exchanges around the world? Place the banhammer on any mention of Bitcoin in the dying/decrepit mainstream media? Buy up/corner/squeeze the market (like silver in 1980)? Pull multiple super pump-and-dumps? Divert some of the USG black budget for a Currency Collapse Prevention team made up of the best NSA hackers to look for some an attack vector/vulnerability? A 51% type of attack involving sabotage of the underseas Internet lines (recall the 2010 incidents that isolated Iran off the Internet) to split the blockchain?
Regardless of what they try, one cannot kill an idea. Cryptocurrencies are an idea whose time has come. It's Game Over for the largest criminal empire the planet has ever seen.
They can do a lot of things, and at least attempt everything you mentioned. The key here will be them attacking the psychology of people who do not yet understand the technology yet. This si your average person, the one who has either not heard of cryptocurrencies yet, or the type of person who thinks all cryptocurrencies are called "bitcoins".
Bear in mind, cryptocurrencies are a technology. The number of people who understand how the technology works, and how it can be very beneficial to own, cannot decrease, unless the individuals who learn about it are individually killed. This is why its value will follow a general upward S-curve as adoption increases. So their focus will be on discouraging technology.
So a main weapon at their disposal is to put discouragement at every venue, from the media to the internet. Keep in mind, many governments own bot software to automatically post opinions in their favor and to astroturf online landscapes and mentalities.
I see a lot of news reports out lately pointing at bitcoin's crash, calling it a bubble, calling them tulips, etc... Older people with a lot of money and a poor understanding of technology will generally agree with such reports, because they are based off of traditional wisdom. As we all know though, traditional wisdom does not apply to cryptocurrencies.
It's a technology and a currency, and these two factors combined together give it a chart that makes it look like a speculative stock investment. And that is how the media are essentially demonizing it. The more people who gain an understanding of cryptocurrency, the better. We can no longer just keep shilling our favorite coins, we need to collectively band together on the public front for more direct explanations of how cryptos can benefit the public.