PT What's up with Sidious' claim in ROTS?

It's helpful to take into account the context of that line:

199 INT. CORRIDOR-SENATE ARENA-CHANCELLOR'S HOLDING OFFICE-NIGHT

MAS AMEDDA leaves the room. PALPATINE approaches a stunned YODA.

DARTH SlDIOUS: I have waited a long time for this moment, my little green friend. At last, the Jedi are no more.

YODA: Not if anything I have to say about it, Lord Sidious.

YODA uses the Force to throw DARTH SIDIOUS back, knocking him clear over his desk and onto the floor in a heap.

YODA: (continuing) At an end your rule is and not short enough it was, I must say.

DARTH SIDIOUS flies through the air, cape flapping, heading toward the exit. At the last second, YODA flies into the exit and stops the Dark Lord.

YODA: (continuing) If so powerful you are, why leave??

YODA ignites his lightsaber.

DARTH SlDIOUS: You will not stop me. Darth Vader will become more powerful than either of us.

DARTH SIDIOUS ignites his lightsaber.

YODA: Faith in your new apprentice, misplaced may be, as is your faith in the dark side of the Force.

Their swords CLASH. The battle is extremely fast and furious.

So you see Sidious starts off the scene arrogantly boasting about his impending total victory over the Jedi, only for Yoda to immediately humble him with a powerful counterattack. At this point Sidious changes course and tries to run away, but Yoda blocks his path and mocks him for the contradiction between his confident words and his fearful actions.

What Sidious is doing here is conceding the point to Yoda. He's saying, Okay, Yoda. Maybe you'll get the better of me here, maybe not. But you won't be able to stop what I'm doing, because Darth Vader is a part of all this now. If you kill me, he'll still be around, and without me to contend with he'll become unstoppable. So even if I go down, I'm taking you and everything you love down with me.

At least, that's how I understand it.

 

Which is clearly something that is not meant as that interpretation simply does not hold withing the context of the movies themselves. Even within the lines themselves it comes off as contradictory in that view:

"And well you should not. For my ally is the Force, and a powerful ally it is. Life creates it, makes it grow. Its energy surrounds us and binds us. Luminous beings are we, not this crude matter."

As you say people take crude to mean meaningless as opposed to the definition which is a raw or natural state.

 

The ultimate goal of a Sith is to create an apprentice more powerful than himself / herself. It goes against the Sith code of gaining and retaining power, and all that. But a Sith master has to expect betrayal at some point, either through sheer power and fighting skill, or via other means (such as murdering your master in his sleep). Both show ambition, and ultimately it creates a stronger lineage. You'd rather this happen, than die with a weak apprentice, knowing all that accumulated knowledge might be lost when HE dies.

 

Really? D: I thought it was pretty obvious when he pinched Luke’s shoulder. He’s talking about the physical flesh, our natural body and how the Jedi transcend that.

 

And they transcend it by communing with the Force via the midi-chlorians. If the physical flesh weren't a factor to be contended with, then neither Luke nor Yoda would be there slapping their crude meat flaps together yapping about it. Their bodies would vanish right on the spot like Obi-Wan's did in the last movie, and then they'd use their unlimited power to zap Vader and the Emperor into smithereens right then and there.

The Force has always been based heavily on the Chinese concept of qi. Qi is something which flows through the body, affects the body, and is affected by the body. The Force is no different.

https://www.bbc.co.uk/religion/religions/taoism/beliefs/concepts.shtml

This is what the Force is based on. Lucas wasn't creating his own, entirely new religion. He isn't L. Ron Hubbard.

 

It's a trash talk, he knew Yoda would feel terrible about losing Anakin.